The thyroid is a small, butterfly-shaped gland at the front of the neck. It releases hormones that control how fast your body uses energy, which affects almost every organ. When the gland makes too little hormone, the condition is called hypothyroidism, or an underactive thyroid. It is one of the most common hormone problems in India and is far more frequent in women than in men.
Common symptoms
Symptoms usually develop slowly over months or years, so they are easy to dismiss as stress or ageing:
- Tiredness and sluggishness even after a full night's sleep
- Weight gain without eating more
- Feeling cold when others are comfortable
- Dry skin, brittle nails and thinning hair
- Constipation
- Puffy face and a hoarse voice
- Heavy or irregular periods, and difficulty conceiving
- Low mood, poor concentration and forgetfulness
- Muscle aches and joint stiffness
What causes it?
- Hashimoto's thyroiditis: an autoimmune condition in which the immune system attacks the thyroid. This is the most common cause.
- Iodine deficiency: less common today thanks to iodised salt, but still seen in some regions.
- After treatment: thyroid surgery or radioactive iodine therapy.
- Pregnancy and after delivery: thyroid function can change during and after pregnancy.
- Certain medicines.
Which tests confirm it?
- TSH (thyroid stimulating hormone): the main screening test. When the thyroid is underactive, the brain releases more TSH to push it harder, so TSH rises.
- Free T4: the actual thyroid hormone in the blood. A low free T4 with a high TSH confirms hypothyroidism.
- Anti-TPO antibodies: show whether an autoimmune cause such as Hashimoto's is present.
Reference ranges vary between labs, but a TSH roughly between 0.4 and 4.0 mIU/L is commonly treated as normal for adults. A mildly raised TSH with normal T4 is called subclinical hypothyroidism; your doctor will decide whether it needs treatment or just monitoring. Pregnant women have different targets.
How is it treated?
Treatment is usually a daily tablet of levothyroxine, a synthetic version of the T4 hormone. The dose is adjusted based on TSH tests every few weeks at first and then once or twice a year. Most people need it lifelong, but once the dose is right, symptoms improve and life is completely normal.
Medicine timing tips
- Take the tablet on an empty stomach with plain water, ideally 30 to 60 minutes before breakfast or tea.
- Keep calcium, iron and antacid tablets at least 4 hours away from your thyroid tablet, as they reduce absorption.
- Take it at the same time every day and do not change brands without telling your doctor.
Diet tips
- Use iodised salt in normal amounts. Extra iodine supplements are not needed unless prescribed.
- Eat a balanced diet with vegetables, fruits, whole grains, dal, eggs, fish or paneer for protein.
- Get enough selenium and zinc from nuts, seeds, eggs and whole grains.
- Cruciferous vegetables such as cabbage and cauliflower are fine when cooked and eaten in normal portions.
- Soy and high-fibre foods can affect tablet absorption, so keep them away from your medicine time.
- Watch portion sizes and stay active, as a slower metabolism makes weight gain easier.
When to see a doctor
Get your thyroid checked if you have several of the symptoms above, a family history of thyroid disease, are planning a pregnancy, or have another autoimmune condition such as type 1 diabetes. A simple blood test is all it takes to find out.
Disclaimer: This article is for general information only and is not medical advice. Please consult a qualified doctor for advice about your own health.
