Hyperthyroidism, also known as overactive thyroid, is a condition where the thyroid gland produces and secretes excessive amounts of thyroid hormones triiodothyronine (T3) and/or thyroxine (T4). Graves' disease, an autoimmune disorder, is the most common cause. Symptoms include weight loss, increased appetite, irritability, weakness, and heat intolerance. Signs include palpitations, tremor, and goiter. The excess thyroid hormone affects nearly every tissue in the body, increasing the body's metabolic rate. Tests can confirm the diagnosis by showing suppressed TSH and elevated free T4 levels, and imaging and antibody tests are also used.

1. HYPERTHYROIDISM
By- Dr. Armaan Singh

2. Hyperthyroidism- often called overactive
thyroid and sometimes hyperthyreosis, is a
condition in which the thyroid gland produces and
secretes excessive amounts of the free
(not protein bound circulating in the blood[1]
) thyroid
hormones -triiodothyronine (T3)
and/or thyroxine (T4). Graves' disease is the most
common cause of hyperthyroidism. The opposite
is hypothyroidism ('sluggish thyroid'), which is the
reduced production and secretion of T3 and/or T4.

3. Thyrotoxicosis or Hyperthyroidism may be
asymptomatic, but when it is not, symptoms are
due to an excess of thyroid hormone. Thyroid
hormone is important at a cellular level, affecting
nearly every type of tissue in the body. Thyroid
hormone functions as a controller of the pace of
all of the processes in the body. This pace is
called the metabolic rate.

4. SYMPTOMS
 Weight loss despite an increased appetite.
 Weight gain.
 Increased or decreased appetite.
 Irritability.
 Weakness and fatigue.
 Diarrhoea ± steatorrhoea.
 Sweating.
 Tremor.
 Mental illness: may range from anxiety to
psychosis.
 Heat intolerance.
 Loss of libido.
 Oligomenorrhoea or amenorrhoea.

5. SIGNS
 Palmar erythema.
 Sweaty and warm palms.
 Fine tremor.
 Tachycardia - may be atrial fibrillation and/or heart failure
(common in the elderly).
 Hair thinning or diffuse alopecia.
 Urticaria, pruritus.
 Brisk reflexes.
 Goitre.
 Proximal myopathy (muscle weakness ± wasting).
 Gynaecomastia.
 Lid lag (may be present in any cause of hyperthyroidism).

6.  Major clinical signs include weight loss (often accompanied by an
increased appetite), anxiety, intolerance to heat, hair loss (especially of
the outer third of the eyebrows), muscle aches, weakness, fatigue,
hyperactivity, irritability, hyperglycemia,
polyuria, polydipsia, delirium, tremor, pretibial myxedema (in Graves'
disease), and sweating. Panic attacks, inability to concentrate,
andmemory problems may also occur. Psychosis and paranoia,
common during thyroid storm, are rare with milder hyperthyroidism.
Many persons will experience complete remission of symptoms 1 to 2
months after a euthyroid state is obtained, with a marked reduction in
anxiety, sense of exhaustion, irritability, and depression. Some
individuals may have an increased rate of anxiety or persistence
of affective and cognitive symptoms for several months to up to 10
years after a euthyroid state is established.In addition, patients may
present with a variety of physical symptoms such
as palpitations and arrhythmias (the notable ones beingatrial
fibrillation), shortness of breath (dyspnea), loss
of libido, amenorrhoea, nausea, vomiting, diarrhea, gynaecomastia an
d feminization. Long term untreated hyperthyroidism can lead
to osteoporosis. These classical symptoms may not be present often in
the elderly.

7. THE MAJOR CAUSES IN HUMANS ARE:
 Graves' disease. An autoimmune disease (usually, the most common
etiology with 50-80% worldwide, although this varies substantially with
location- i.e., 47% in Switzerland (Horst et al., 1987) to 90% in the USA
(Hamburger et al. 1981)). Thought to be due to varying levels of iodine in
the diet.
 Toxic thyroid adenoma (the most common etiology in Switzerland, 53%,
thought to be atypical due to a low level of dietary iodine in this country)[13]
 Toxic multinodular goitre.
 High blood levels of thyroid hormones (most accurately
termed hyperthyroxinemia) can occur for a number of other reasons:
 Inflammation of the thyroid is called thyroiditis. There are several different
kinds of thyroiditis including Hashimoto's thyroiditis (Hypothyroidism
immune-mediated), and subacute thyroiditis (DeQuervain's). These may
be initially associated with secretion of excess thyroid hormone, but usually
progress to gland dysfunction and, thus, to hormone deficiency and
hypothyroidism.
 Oral consumption of excess thyroid hormone tablets is possible
(surreptitious use of thyroid hormone), as is the rare event of consumption
of ground beef contaminated with thyroid tissue, and thus thyroid hormone
(termed "hamburger hyperthyroidism").

8. INVESTIGATIONS
 Thyroid function tests (TFTs): serum TSH can exclude primary
thyrotoxicosis. Confirm the diagnosis with free T4 levels. If TSH is
suppressed but free T4 levels are normal.
 Autoantibodies - these are most commonly seen in Graves' disease:
 Imaging: Thyroid ultrasound scan.