Autonomic Neuropathy may involve the cardiovascular, gastrointestinal, genitourinary systems and the sweat glands.
Patients with generalized autonomic neuropathies may report ataxia, gait instability, or near syncope/syncope. In addition, autonomic neuropathies have further symptoms that relate to the anatomic site of nerve damage—gastrointestinal, cardiovascular, bladder, or sudomotor.
– Gastrointestinal autonomic neuropathy may produce the following symptoms:
Dysphagia, abdominal pain, nausea/vomiting, malabsorption, faecal incontinence, diarrhoea, constipation.
– Cardiovascular autonomic neuropathy may produce the following symptoms :
Persistent sinus tachycardia, orthostatic hypotension, sinus arrhythmia, decreased heart variability in response to deep breathing, near syncope upon changing positions from recumbent to standing.
– Bladder neuropathy (which must be differentiated from prostate or spine disorders) may produce the following symptoms:
Poor urinary stream
Feeling of incomplete bladder emptying
Straining to void
– Sudomotor neuropathy may produce the following symptoms:
Heat intolerance
Heavy sweating of head, neck, and trunk with anhidrosis of lower trunk and extremities
Gustatory sweating

Sildenafil administration to patients who are using organic nitrates, either regularly and/or intermittently, in any form is contraindicated.
Organic nitrates and nitric oxide (NO) donors exert their therapeutic effects on blood pressure and vascular smooth muscle by the same mechanism as endogenous NO via increasing cGMP concentrations.

In patients with polycystic ovarian syndrome (PCOS), FSH levels are within the reference range or low. Luteinizing hormone (LH) levels are elevated for Tanner stage, sex, and age. The LH-to-FSH ratio is usually greater than 3.

Women with PCOS have abnormalities in the metabolism of androgens and oestrogen and in the control of androgen production. PCOS can result from abnormal function of the hypothalamic-pituitary-ovarian (HPO) axis.
The major features of PCOS include menstrual dysfunction, anovulation, and signs of hyperandrogenism. Other signs and symptoms of PCOS may include the following:
– Hirsutism
– Infertility
– Obesity and metabolic syndrome
– Diabetes
– Obstructive sleep apnoea

Androgen excess can be tested by measuring total and free testosterone levels or a free androgen index. An elevated free testosterone level is a sensitive indicator of androgen excess. Other androgens, such as dehydroepiandrosterone sulphate (DHEA-S), may be normal or slightly above the normal range in patients with polycystic ovarian syndrome (PCOS). Levels of sex hormone-binding globulin (SHBG) are usually low in patients with PCOS.

Some women with PCOS have insulin resistance and an abnormal lipid profile (cholesterol >200 mg/dL; LDL >160 mg/dL). Approximately one-third of women with PCOS who are overweight have impaired glucose tolerance or type 2 diabetes mellitus by 30 years of age.

Androgen insensitivity syndrome (AIS), previously referred to as testicular feminization, is an X-linked disorder in which the patients are genotypically male (possessing and X and Y chromosome) and phenotypically female. This disorder is rare, with reported incidences from 1 in 20,000 to 1 in 60,000 live male births, and is the result of a missing gene on the X chromosome that is responsible for the cytoplasmic or nuclear testosterone receptor. In its absence, the gonad, which is a testis, produces normal amounts of testosterone; however, the end tissues are unable to respond due to the deficient receptors leading to the external genitalia developing in a female fashion. Anti-mullerian hormone, which is produced by the testis, is normal in these patients, leading to regression of the Mullerian duct. Wolffian duct development, which depends on testosterone, does not occur as the ducts lack the receptors.
The cumulative effect is a genotypic male with normal external female genitalia (without pubic or axillary hair), no menses, normal breast development, short or absent vagina, no internal sex organs, and the presence of testis. Frequently, these patients have bilateral inguinal hernias in childhood, and their presence should arouse suspicion of the diagnosis.

The patient most likely has Klinefelter’s syndrome.
Klinefelter syndrome (KS) refers to a group of chromosomal disorders in which the normal male karyotype, 46,XY, has at least one extra X chromosome. XXY aneuploidy, the most common human sex chromosome disorder. It is also the most common chromosomal disorder associated with male hypogonadism and infertility.
Klinefelter syndrome is characterized by hypogonadism (micro-orchidism, oligospermia/azoospermia), gynecomastia in late puberty, hyalinization and fibrosis of the seminiferous tubules, elevated urinary gonadotropin levels, and behavioural concerns.

Raloxifene is a selective oestrogen-receptor modulator (SERM) that has been approved for use in the prevention and treatment of osteoporosis in postmenopausal women.
A SERM interacts with oestrogen receptors, functioning as an agonist in some tissues and an antagonist in other tissues. Because of their unique pharmacologic properties, these agents can achieve the desired effects of oestrogen without the possible stimulatory effects on the breasts or uterus.

Hashimoto thyroiditis is the most common cause of hypothyroidism in developed countries. In contrast, worldwide, the most common cause of hypothyroidism is an inadequate dietary intake of iodine. This disease is also known as chronic autoimmune thyroiditis and chronic lymphocytic thyroiditis.

Graves’ disease is the most common cause of thyrotoxicosis in pregnancy.

– Poor control of thyrotoxicosis is associated with pregnancy loss, pregnancy-induced hypertension, prematurity, low birth weight, intrauterine growth restriction, stillbirth, thyroid storm, and maternal congestive heart failure.

– Antithyroid drugs are the treatment of choice of hyperthyroidism during pregnancy. The lowest dose of ATD needed to maintain TT4 1.5× the upper limit of the non-pregnant reference range or FT4 at the upper limit of the reference range should be used.
Two different antithyroid drug (ATD) regimens are in common use for Grave’s disease: i) Titration method and ii) Block-and-replace method.
In the titration method, the usual starting dose is 15–30 mg/day methimazole (or equivalent doses of other thionamides); further to periodic thyroid status assessment, daily dose is tapered down to the lowest effective dose (avoiding both hyper- and hypothyroidism).
The block-and-replace method uses persistently high ATD doses in association with L-thyroxine replacement to avoid hypothyroidism; treatment lasts 6 months. This method has advantages and disadvantages over the titration method. Higher doses of ATDs may have a greater immunosuppressive action useful for a permanent remission of hyperthyroidism, but this effect remains to be demonstrated.
Avoidance of hypothyroidism or ‘escape’ of hyperthyroidism seems easier than with the titration method; treatment is shorter, and the number of visits lower. On the other hand, the much higher number of tablets taken every day may create problems of poor compliance. The block-and-replace method should not be used during pregnancy.

– Breastfeeding has been shown to be safe in mothers taking ATDs in appropriate doses.

Several dipeptidyl peptidase-4 (DPP-4) inhibitors are in clinical development; these are orally active and increase levels of active glucagon-like peptide-1 (GLP-1), which in turn increases insulin secretion and reduces glucagon secretion, thereby lowering glucose levels.
Sitagliptin and vildagliptin both have a long duration of action, allowing once-daily administration. Both sitagliptin and vildagliptin are safe and tolerable with a low risk of hypoglycaemia. In drug-naïve subjects with type 2 diabetes, both sitagliptin and vildagliptin reduce A1C levels by ,1% as monotherapy.

Primary aldosteronism now is considered one of the more common causes of secondary hypertension (HTN).
Individuals with primary aldosteronism may present with hypokalaemia metabolic alkalosis; however, as many as 38% of patients with primary aldosteronism may be normokalaemia at presentation.
Routine laboratory studies can show hypernatremia, hypokalaemia, and metabolic alkalosis resulting from the action of aldosterone on the renal distal convoluted tubule (DCT) (i.e., enhancing sodium reabsorption and potassium and hydrogen ion excretion).
Plasma aldosterone/plasma renin activity ratio is used for screening because it is fairly constant over many physiologic conditions.

The patient is clinically free, so Cushing diseases can be exclude.

Carcinoid tumours are of neuroendocrine origin and derived from primitive stem cells in the gut wall, especially the appendix. They can be seen in other organs, including the lungs, mediastinum, thymus, liver, bile ducts, pancreas, bronchus, ovaries, prostate, and kidneys. While carcinoid tumours tend to grow slowly, they have the potential to metastasise.
Signs and symptoms seen in larger tumours may include the following:
– Periodic abdominal pain: Most common presentation for a small intestinal carcinoid; often associated with malignant carcinoid syndrome.
– Cutaneous flushing: Early and frequent (94%) symptom; typically affects head and neck.
– Diarrhoea and malabsorption (84%): Watery, frothy, or bulky stools, gastrointestinal (GI) bleed or steatorrhea; may or may not be associated with abdominal pain, flushing, and cramps.
– Cardiac manifestations (60%): Valvular heart lesions, fibrosis of the endocardium; may lead to heart failure with tachycardia and hypertension.
– Wheezing or asthma-like syndrome (25%): Due to bronchial constriction; some tremors are relatively indolent and result in chronic symptoms such as cough and dyspnoea.
– Pellagra with scale-like skin lesions, diarrhoea and mental disturbances.
– Carcinoid crisis can be the most serious symptom of the carcinoid tumours and life-threatening. It can occur suddenly or after stress, including chemotherapy and anaesthesia.

Three classes of medications are appropriate for the management of major triglyceride elevations: fibric acid derivatives, niacin, and omega-3 fatty acids.

Fibrate is used as a first-line agent for reduction of triglycerides in patients at risk for triglyceride-induced pancreatitis.

High-dose niacin (vitamin B-3) (1500 or more mg/d) decreases triglyceride levels by at least 40% and can raise HDL cholesterol levels by 40% or more. Niacin also reliably and significantly lowers LDL cholesterol levels, which the other major triglyceride-lowering medications do not.

Omega-3 fatty acids are attractive because of their low risk of major adverse effects or interaction with other medications. At high doses (>4 g/d), triglycerides are reduced.

The thymus is a lymphoid organ located in the anterior mediastinum. In early life, the thymus is responsible for the development and maturation of cell-mediated immunologic functions. The thymus is composed predominantly of epithelial cells and lymphocytes. Precursor cells migrate to the thymus and differentiate into lymphocytes. Most of these lymphocytes are destroyed, with the remainder of these cells migrating to tissues to become T cells.
DiGeorge’s syndrome (DGS) is a developmental abnormality affecting the thymus. The classic triad of features of DGS on presentation is conotruncal cardiac anomalies, hypoplastic thymus, and hypocalcaemia (resulting from parathyroid hypoplasia).

The clinical manifestations of Small cell lung cancer (SCLC) can result from local tumour growth, intrathoracic spread, distant spread, and/or paraneoplastic syndromes.
Hypertrophic pulmonary osteoarthropathy (HPO) is a rare paraneoplastic syndrome that is frequently associated with lung cancer; however, the incidence of clinically apparent HPO is not well known.
SIADH is present in 15% of cases and most commonly seen.
Although hypercalcaemia is frequently associated with malignancy, it is very rare in small cell lung cancer despite the high incidence of lytic bone metastases.
Ectopic Cushing’s syndrome in SCLC does not usually exhibit the classic signs of Cushing’s syndrome and Cushing’s syndrome could also appear during effective chemotherapy.
Chemotherapy is the treatment of choice in SCLC.

Glucagon-like peptide 1 (GLP-1) is a 30-amino acid peptide hormone produced in the intestinal epithelial endocrine L-cells by differential processing of proglucagon. GLP-1 is released in response to meal intake.
The main actions of GLP-1 are to stimulate insulin secretion (i.e., to act as an incretin hormone) and to inhibit glucagon secretion, thereby contributing to limit postprandial glucose excursions. It also inhibits gastrointestinal motility and secretion and thus acts as an enterogastrone and part of the ileal brake mechanism. GLP-1 also appears to be a physiological regulator of appetite and food intake.
Decreased secretion of GLP-1 may contribute to the development of obesity, and exaggerated secretion may be responsible for postprandial reactive hypoglycaemia.

Hyperthyroid patients show significantly lower resting arterial CO2 tension, tidal volume and significantly higher mean inspiratory flow and pa(O2) than healthy patients. This may of course lead to misdiagnosis of patients with hyperthyroidism as having hyperventilation syndrome.

The combination of Insulinoma and Parathyroid diseases is suggestive of MEN 1 syndrome.
Multiple endocrine neoplasia type 1 (MEN1) is a rare hereditary tumour syndrome inherited in an autosomal dominant manner and characterized by a predisposition to a multitude of endocrine neoplasms primarily of parathyroid, entero-pancreatic, and anterior pituitary origin, as well as non-endocrine neoplasms.
Other endocrine tumours in MEN1 include foregut carcinoid tumours, adrenocortical tumours, and rarely pheochromocytoma. Nonendocrine manifestations include meningiomas and ependymomas, lipomas, angiofibromas, collagenomas, and leiomyomas.

Primary hyperparathyroidism (PHPT), due to parathyroid hyperplasia is the most frequent and usually the earliest expression of MEN-1, with a typical age of onset at 20–25 years.

Mild deficiencies of 21-hydroxylase or 3-beta-hydroxysteroid dehydrogenase activity may present in adolescence or adulthood with oligomenorrhea, hirsutism, and/or infertility. This is termed nonclassical adrenal hyperplasia.
Late-onset or nonclassical congenital adrenal hyperplasia (NCAH) due to 21-hydroxylase deficiency is one of the most common autosomal recessive disorders. Reported prevalence ranges from 1 in 30 to 1 in 1000. Affected individuals typically present due to signs and symptoms of androgen excess.
Treatment needs to be directed toward the symptoms. Goals of treatment include normal linear growth velocity, a normal rate of skeletal maturation, ‘on-time’ puberty, regular menstrual cycles, prevention of or limited progression of hirsutism and acne, and fertility. Treatment needs to be individualized and should not be initiated merely to decrease abnormally elevated hormone concentrations.
Normal Ultrasound rules out Turner’s syndrome.

The patient has hyperthyroidism and its most common cause is Grave’s Disease.
Grave’s Disease is an autoimmune disease due to circulating autoantibodies known as TSH receptor stimulating autoantibodies or Thyroid-stimulating immunoglobulins (TSIs) that bind to and activate thyrotropin receptors, causing the thyroid gland to grow and the thyroid follicles to increase the synthesis of thyroid hormone.

Euthyroid sick syndrome (also known as nonthyroidal illness syndrome) can be described as abnormal findings on thyroid function tests that occurs in the setting of a nonthyroidal illness (NTI), without pre-existing hypothalamic-pituitary and thyroid gland dysfunction. After recovery from an NTI, these thyroid function test result abnormalities should be completely reversible.
Multiple alterations in serum thyroid function test findings have been recognized in patients with a wide variety of NTIs without evidence of pre-existing thyroid or hypothalamic-pituitary disease. The most prominent alterations are low serum triiodothyronine (T3) and elevated reverse T3 (rT3), leading to the general term low T3 syndrome. Thyroid-stimulating hormone (TSH), thyroxine (T4), free T4 (FT4), and free T4 index (FTI) also are affected in variable degrees based on the severity and duration of the NTI. As the severity of the NTI increases, both serum T3 and T4 levels drop, but they gradually normalize as the patient recovers.
Reverse T3 is used to differentiate between this condition and secondary thyroid failure.

Osteopenia is an early sign of bone weakening that is less severe than osteoporosis.
The numerical result of the bone density test is quantified as a T score. The lower the T score, the lower the bone density. T scores greater than -1.0 are considered normal and indicate healthy bone. T scores between -1.0 and -2.5 indicate osteopenia. T scores lower than -2.5 indicate osteoporosis.
DEXA also provides the patient’s Z-score, which reflects a value compared with that of person matched for age and sex.
Z-score values of –2.0 SD or lower are defined as below the expected range for age and those above –2.0 SD as within the expected range for age.

European guidelines for the treatment of syndrome of inappropriate antidiuresis include the following recommendations for the management of moderate or profound hyponatremia:
– Restrict fluid intake as first-line treatment.
– Second-line treatments include increasing solute intake with 0.25–0.50 g/kg per day or a combination of low-dose loop diuretics and oral sodium chloride.
– Use of lithium, demeclocycline, or vasopressin receptor antagonists is not recommended.
Recommendations on the treatment of SIADH from an American Expert Panel included the following:
– If chronic, limit the rate of correction.
– Fluid restriction should generally be first-line therapy.
– Consider pharmacologic therapies if serum Na + is not corrected after 24-48 hr of fluid restriction or if the patient has a low urinary electrolyte free water excretion.
– Patients being treated with vaptans should not be on a fluid restriction initially.
– Water, 5% dextrose or desmopressin can be used to slow the rate of correction if the water diuresis is profound.

Primary hyperaldosteronism, also known as Conn’s Syndrome, is one of the most common causes of secondary hypertension (HTN).
The common clinical scenarios in which the possibility of primary hyperaldosteronism should be considered include the following:
– Patients with spontaneous or unprovoked hypokalaemia, especially if the patient is also hypertensive
– Patients who develop severe and/or persistent hypokalaemia in the setting of low to moderate doses of potassium-wasting diuretics
– Patients with treatment-refractory/-resistant hypertension (HTN)
Patients with severe hypokalaemia report fatigue, muscle weakness, cramping, headaches, and palpitations. They can also have polydipsia and polyuria from hypokalaemia-induced nephrogenic diabetes insipidus. Long-standing HTN may lead to cardiac, retinal, renal, and neurologic problems, with all the associated symptoms and signs.

Paget disease is a localized disorder of bone remodelling that typically begins with excessive bone resorption followed by an increase in bone formation. This osteoclastic over activity followed by compensatory osteoblastic activity leads to a structurally disorganized mosaic of bone (woven bone), which is mechanically weaker, larger, less compact, more vascular, and more susceptible to fracture than normal adult lamellar bone.
Approximately 70-90% of persons with Paget disease are asymptomatic; however, a minority of affected individuals experience various symptoms, including the following:
– Bone pain (the most common symptom)
– Secondary osteoarthritis (when Paget disease occurs around a joint)
– Bony deformity (most commonly bowing of an extremity)
– Excessive warmth (due to hypervascularity)
– Neurologic complications (caused by the compression of neural tissues)
Measurement of serum alkaline phosphatase—in some cases, bone-specific alkaline phosphatase (BSAP)—can be useful in the diagnosis of Paget disease. Elevated levels of urinary markers, including hydroxyproline, deoxypyridinoline, C-telopeptide, and N -telopeptide, may help identify patients with Paget disease.
Serum calcium and phosphate levels should be within the reference range in patients with Paget disease.

Hashimoto thyroiditis is part of the spectrum of autoimmune thyroid diseases (AITDs) and is characterized by the destruction of thyroid cells by various cell- and antibody mediated immune processes. It usually presents with hypothyroidism, insidious in onset, with signs and symptoms slowly progressing over months to years.

The diagnosis of Hashimoto thyroiditis relies on the demonstration of circulating antibodies to thyroid antigens (mainly thyroperoxidase and thyroglobulin) and reduced echogenicity on thyroid sonogram in a patient with proper clinical features.

Thyroid storm, also referred to as thyrotoxic crisis, is an acute, life-threatening, hypermetabolic state induced by excessive release of thyroid hormones (THs) in individuals with thyrotoxicosis.
Patients with thyroid storm should be treated in an ICU setting for close monitoring of vital signs and for access to invasive monitoring and inotropic support, if necessary.
– Supportive measures
If needed, immediately provide supplemental oxygen, ventilatory support, and intravenous fluids. Dextrose solutions are the preferred intravenous fluids to cope with continuously high metabolic demand.
– Correct electrolyte abnormalities.
– Treat cardiac arrhythmia, if necessary.
– Aggressively control hyperthermia by applying ice packs and cooling blankets and by administering acetaminophen (15 mg/kg orally or rectally every 4 hours).
– Antiadrenergic drugs.
– Thionamides: Correct the hyperthyroid state. Administer antithyroid medications to block further synthesis of thyroid hormones (THs).
High-dose propylthiouracil (PTU) or methimazole may be used for treatment of thyroid storm.
– Administer glucocorticoids to decrease peripheral conversion of T4 to T3. This may also be useful in preventing relative adrenal insufficiency due to hyperthyroidism and improving vasomotor symptoms.
– Bile acid sequestrants prevent reabsorption of free THs in the gut (released from conjugated TH metabolites secreted into bile through the enterohepatic circulation).
– Treat the underlying condition.

Exogenous thyroid hormone use has been associated with episodes of thyroid storm as well as thyrotoxic periodic paralysis.
It presents with marked proximal muscle weakness in both upper and lower limbs, hypokalaemia and signs of hyperthyroidism.
Hyperthyroidism generally presents with tachycardia, hypertension, hyperthermia, and cardiac arrhythmias

Laxatives and diuretics can result in electrolyte abnormalities.
Medical complications associated with laxatives include chronic diarrhoea which disrupts the normal stool electrolyte concentrations that then leads to serum electrolyte shifts; acutely, hypokalaemia is most typically seen. The large intestine suffers nerve damage from the chronic laxative use that renders it unable to function properly. The normal peristalsis and conduction are affected; the disorder is thought to be secondary to a degeneration of Auerbach’s Plexi. However, it does not cause muscle weakness.

Insulin tends to cause weight gain, not weight loss.
Metformin does not cause muscle weakness but can cause headaches.

Thyroid malignancies are divided into papillary carcinomas (80%), follicular carcinomas (10%), medullary thyroid carcinomas (5-10%), anaplastic carcinomas (1-2%), primary thyroid lymphomas (rare), and primary thyroid sarcomas (rare).
Hürthle cell carcinoma is a rare thyroid malignancy that is often considered a variant of follicular carcinoma.
– Papillary and Follicular carcinoma are slow-growing tumours
– Sporadic cases of Medullary thyroid carcinoma also typically manifest with painless solitary thyroid nodules in the early stages.
– Anaplastic thyroid carcinoma has the most aggressive biologic behaviour of all thyroid malignancies and has one of the worst survival rates of all malignancies in general. It manifests as a rapidly growing thyroid mass in contrast to a well-differentiated carcinoma, which are comparatively slow-growing. Patients commonly present with associated symptoms due to local invasion. Hoarseness and dyspnoea resulting from the involvement of the recurrent laryngeal nerve and airway occur in as many as 50% of patients.
– Almost all patients with primary thyroid lymphoma have either a clinical history or histological evidence of chronic lymphocytic thyroiditis. The risk of primary thyroid lymphoma increases 70-fold in patients with chronic lymphocytic thyroiditis compared with the general population. Regional and distant lymphadenopathy is common.

The patient has hyperprolactinaemia with otherwise normal oestradiol, FSH and LH. This is highly suggestive of Prolactinoma rather than a non functioning tumour.
In polycystic ovaries, there is increase in the level of LH while FSH is normal or low.

The patient has hyperinsulinemia and hypoglycaemia, but her C-peptide levels are normal. This is strongly suggestive of the fact that she is self-administering insulin.
In Insulinoma, common diagnostic criteria include:
– blood glucose level < 50 mg/dl with hypoglycaemic symptoms,
– relief of symptoms after eating
– absence of sulfonylurea on plasma assays.
The classic diagnostic criteria include the demonstration of the following during a supervised fast:
Increased plasma insulin level
Increased C peptide level
Increased proinsulin level
However, the patient has normal C-peptide levels.
In type-1 diabetes mellitus, insulin and C-peptide levels are low.