Thyroid Problems, Disease : Causes, Symptoms, Diagnosis

The thyroid gland problems are explained including symptoms, causes and diagnosis of underactive, low and overactive thyroid disease.

Thyroid Gland

The thyroid gland is a butterfly-shaped gland in the front of the neck and just below Adam's apple. It is made up of two lobes of plum size cut into half, the left and the right lobes. The two lobes are joined by a small bridge of isthmus tissue and lie on either side of the wind pipe .

Function of Thyroid

The function of thyroid gland is to control a wide range of the body's metabolic processes. It produces hormones that control our metabolism, growth, fertility, body temperature, etc., so it's proper function is essential for our well-being.

How Thyroid Gland Works

It works in conjunction with the pituitary gland which is at the base of the brain. The pituitary gland senses the level of thyroid hormones in the blood. When the normal levels drop, the pituitary gland produces a hormone TSH (Thyroid Stimulating Hormone) which activates the gland to secrete more T3 and T4 hormones.

When the hormone levels rise above normal, the pituitary senses this and stops secreting TSH so that the thyroid gland makes less hormones. This is how T3 and T4 hormones secreted by the thyroid gland is regulated so that just the right amounts are manufactured and delivered into the blood stream.

Thyroid Hormones T3 & T4

The gland uses iodine from food and produce two hormones, T3 (Tri-iodothyronine, contains 3 iodine atoms) and T4 (thyroxine contains 4 iodine atoms). It produces primarily T4 with only very small amounts of T3. The majority of T3 present in the blood is produced by conversion of T4 to T3 primarily in the liver. The thyroid gland stores these hormones and releases them as they are needed.

These hormones determine how slow or how fast our organs work. Too much deviations from the optimal natural thyroid function may many times be the underlying cause of a number of serious conditions. Stress, trauma, infections, certain medications and temperature fluctuations change the amount of thyroid hormone required by the body. The pituitary gland (hypothalamus) in the brain ensures the normal levels of T3 and T4.

Causes of High TSH Levels

An underactive thyroid (hypothyroidism)
A pituitary gland tumor that is making too much TSH. This is uncommon.
Not taking enough thyroid hormone medicine for treatment of an underactive thyroid gland.

Causes of Low TSH levels

An overactive thyroid gland.
Damage to the pituitary gland.
Taking too much thyroid medicine for treatment of an underactive thyroid gland.
Pregnancy during the first trimester.

Thyroid cancer

The cancer of the thyroid gland is rare. Most lumps or nodules in the neck are non-cancerous. The thyroid cancer can also be treated with success by the modern treatments.

Thyroid Disease and Disorders

The thyroid problems are diagnosed by blood tests for thyroid hormones. The thyroid gland can have the following diseases:

Hypothyroidism
Hyperthyroidism
Hypothyroidism in pregnancy: After the delivery it is generally cured by itself.
Hyperthyroidism in pregnancy: After the delivery it is generally cured by itself.
Thyroid nodule or solid or fluid-filled lumps are found commonly as people age. Most of these thyroid nodules are benign and not cancerous.
Post-partum thyroid disease
Thyroid cancer

Hypothyroidism : Underactive Thyroid

The underactive thyroid disease is due to low thyroid or hypothyroidism. The thyroid becomes underactive, due to which it makes too little thyroid hormone (Low T4) than the body needs. This is the most common type of thyroid disease.

The extent of hypothyroidism symptoms depend on age, duration of hypothyroidism and the seriousness of the condition. The signs of low thyroid may be so mild that they are not noticed for several years. These are noticeable if you are old.

The common underactive thyroid symptoms are as under:

Fatigue and weakness are the common symptoms of low underactive thyroid.
Low basal temperature and cold intolerance
Cold hands and feet
Dry skin, yellowish tint to the skin
Sleep difficulty
Constipation
Depression
Hair loss, thinning hair
Brittle nails
Weak memory, depression, difficulty in concentrating
Nervousness and tremors, slow body movements
Weakness, tired
Muscle weakness, muscle aches and stiffness
Stiffness or swelling in joints
High blood cholesterol
Immune system problems
Heavy or irregular menstrual periods lasting longer than 5 to 7 days
Weight gain
Less common symptom: swelling of arms, hands, legs, feet and face, puffiness of eyes, hoarse voice, enlarged thyroid (goiter)

Signs and symptoms of advanced hypothyroidism, known as myxedema, include low blood pressure, low body temperature, decreased breathing, unresponsiveness and even coma. It can be life threatening but it is rare.

Causes of hypothyroidism

Congenital: Present from birth.
Defects in the production of thyroid hormone: Hashimoto thyroiditis, goiter
Surgical removal of thyroid tissue.
Antithyroid antibodies

Hyperthyroidism: Overactive Thyroid

The overactive thyroid disease is due to too much thyroid or hyperthyroidism. In hyperthyroidism, the thyroid system becomes overactive, due to which thyroid gland produces too much thyroid hormone (High T4). The common symptoms are as under:

Palpitations, fast heart rate, breathlessness
Heat intolerance
Weight loss
Light or no menstrual periods
Fatigue and weakness
Muscle weakness, trembling hands, nervousness
Warm hands and feet
Insomnia
Heat intolerance

Causes of hyperthyroidism

Grave's disease
Pituitary adenoma tumor of the pituitary gland
Thyroiditis, an inflammatory disorder of the thyroid gland
Toxic multi-nodular goiter
Some heart medication like amiodarone.

The content on this website is reviewed regularly and is updated when new information is made available. The information provided is neither intended nor implied to be a substitute for professional medical advice. You should always seek the advice of your Doctor.

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