Hypothyroidism: Symptoms, Causes & Treatment!

Hypothyroidism also called as an underactive thyroid is a condition in which the thyroid gland does not produce thyroid hormone as per requirement.

It is a disorder of the endocrine system.


SIGNS & SYMPTOMS OF HYPOTHYROIDISM

  • Fatigue
  • Chills
  • Problems with memory & concentration
  • Constipation
  • Dyspepsia
  • Dry coarse skin
  • Weight gain
  • Loss of appetite
  • Shortness of breath
  • Hoarse voice
  • Heavy menstruation in women
  • Hair loss
  • Abnormal sensation
  • Poor hearing.


COMPLICATIONS

  • A rare condition of extreme hypothyroidism, called myxedema coma;
  • Low body temperature
  • Extremities of the body are cold
  • Confusion
  • Slow heart rate
  • Reduced breathing rate
  • Swelling/Fluid accumulation in the legs
  • Delayed reflex & reaction
  • Enlargement of the tongue
  • Carpal tunnel syndrome
  • Fluid accumulation in the heart cavity
  • Fluid accumulation in the lungs
  • Also fluid accumulation in the liver.

In pregnancy

  • Infertility
  • Increased risk of miscarriage
  • An offspring with lower intelligence
  • Infant death after birth
  • Gestational diabetes
  • Premature birth (even before 37 weeks of pregnancy)

In Children

  • Abnormal birth weight & height
  • Enlarged head & tongue
  • Dry skin & decreased muscle tone
  • Low body temperature
  • Drowsiness & intellectual impairment
  • Delayed puberty


CAUSES OF HYPOTHYROIDISM

  • Inadequate function of the thyroid gland (primary hypothyroidism)
  • Inadequate function of the pituitary gland. The pituitary gland is responsible for secretion of the thyroid stimulating hormone (TSH). (secondary hypothyroidism)
  • Inadequate function of the hypothalamus, by decreased secretion of thyrotropin releasing hormone.
  • Autoimmune disease called Hashimoto’s thyroiditis
  • Postpartum thyroiditis
  • Deficiency of iodine in the diet

 

RISK FACTORS

  • Various types of thyroid inflammation
  • Previous thyroid surgery
  • Previous radioiodine therapy
  • Drugs like lithium & amiodarone
  • Cancer of the pituitary gland
  • Cancer of the meninges
  • Surgery of the pituitary gland
  • Bursting of the internal carotid artery
  • Overload of iron in the blood
  • Diabetes
  • Lupus
  • Myasthenia gravis
  • Rheumatoid arthritis
  • Infections like tuberculosis & syphilis
  • Congenital related hypothyroidism due to iodine deficiency in the pregnant mother
  • Mutations in the chromosomes.


DIAGNOSIS

  1. Measurement of TSH levels:
    a) Laboratory testing of TSH levels in the blood. Two tests are done separated by 2 weeks.
    b) A low level of TSH indicates as central hypothyroidism due to inadequate function of the pituitary gland.
    c) When the TSH level is more than 5mlU/L but the levels of T3 & T4 are low, the conditioned is diagnosed as overt hypothyroidism.
    d) When the TSH level is ranging between 5-10mlU/L, but the serum level of T3 & T4 is normal, it is diagnosed as a milder form of hypothyroidism called as Hashimoto’s thyroiditis.
  2. Testing of the levels of creatine kinase, liver enzymes, cholesterol & LDL, since their levels usually are elevated in hypothyroidism.
  3. In severe hypothyroidism, a low sodium level in blood is associated along with low level of anti-diuretic hormone & worsening of kidney function.
  4. Imaging of the thyroid gland for detection of any abnormal lumps.
  5. Biopsy of the thyroid gland for differential diagnosis.
  6. In pregnancy:
    a) The TSH level when between 2.5-5mlU/L or when over 10mlU/L, can be cause of hypothyroidism.
    b) Free thyroxine levels are low during to incomplete binding to albumin.
    c) Detection of presence of antibodies against TPO.
  7. Assessment of the dietary iodine & the level of iodine absorbed by the the thyroid gland by radioiodine test.
  1. Screening for hypothyroidism is performed in the newborn period in many countries, generally using TSH.


TREATMENT FOR HYPOTHYROIDISM

  • Synthetic thyroxine is the primary medication for hypothyroidism in the form of levothyroxine.
  • The dosage depends on the age & underlying condition of the patients, although usually one dose daily is prescribed.
  • Levothyroxine is given in combination dose with liothyronine (synthetic T3) for better management of symptoms.
  • Desiccated thyroid extract is an animal-based thyroid gland extract, most commonly from pigs. It is a combination therapy, containing forms of T4 and T3.
  • Calcitonin is also added along with it, which is required for regulation of calcium in the body.
  • No treatment required when the level of TSH is between 10-20 mlU/L.
  • In severe hypothyroidism like myxedema, admission to intensive care is required.
  • Breathing aid is provided by mechanical ventilation.
  • Monitoring of sodium levels by prescribing a saline solution.
  • Corticosteroids for management of adrenal insufficiency.
  • Fluid replacement
  • Vasopressor agents for management of low blood pressure.
  • Administration of thyroid hormones by a nasogastric tube.


MANAGEMENT & PREVENTION

  • Hypothyroidism is preventable by adding iodine to commonly used foods.
  • More consumption of iodine rich foods like fish & dairy products.
  • Iodine deficiency is treatable by addition of iodine in salt.
  • Dosage of 250 micrograms of iodine is recommended for pregnant & breast feeding women.