Thyroid Disorders: Hypothyroidism, Hyperthyroidism and How to Take Thyroid Medicine

A tiny gland in the neck sets the pace for your whole body. When the thyroid works too slowly, you feel tired, cold and heavy. When it works too fast, you feel shaky, hot and anxious. Thyroid disorders are very common in Pakistan, especially among women, and many people go for years before it is diagnosed, because the symptoms look like ordinary tiredness or stress.

This guide explains underactive and overactive thyroid, the tests, how thyroid medicines such as levothyroxine and carbimazole are used, how to take them correctly, and what affects your treatment.

What does the thyroid do?

The thyroid gland makes hormones (T3 and T4) that control metabolism: how fast your body uses energy, your heart rate, temperature, digestion, mood, periods and growth. The brain regulates it through thyroid-stimulating hormone (TSH).

Underactive thyroid (hypothyroidism)

This is the most common thyroid problem. The gland makes too little hormone.

• Symptoms: tiredness, weight gain, feeling cold, dry skin, hair loss, constipation, slow heartbeat, low mood, muscle aches, heavy or irregular periods, puffy face, a hoarse voice and difficulty concentrating.
• Causes: Hashimoto’s thyroiditis (an autoimmune disease) is the commonest cause. Others include iodine deficiency, previous thyroid surgery or radioiodine, and some medicines.
• In babies: untreated hypothyroidism at birth can affect brain development, and this is why newborn screening is important.

Overactive thyroid (hyperthyroidism)

• Symptoms: weight loss despite eating well, palpitations, tremor, heat intolerance and sweating, anxiety, irritability, loose motions, light periods, trouble sleeping, and sometimes bulging eyes or a swelling in the neck (goitre).
• Causes: Graves’ disease (an autoimmune condition), thyroid nodules, and thyroiditis.

An overactive thyroid can feel like anxiety. See our guide to depression and anxiety medicines, and our article on excessive sweating, which may have a thyroid cause.

Tests

• TSH is the first test. In hypothyroidism, TSH is high, and in hyperthyroidism it is low.
• Free T4 and sometimes free T3 confirm the diagnosis.
• Thyroid antibodies (anti-TPO, TRAb) help find the cause.
• Ultrasound for lumps or enlargement, and sometimes a scan or needle test.

If you take biotin (vitamin B7, often in hair and nail supplements), tell your doctor and stop it for a few days before the test if advised. Biotin can give false results. See our guide to hair regrowth treatments.

Medicines for hypothyroidism

The standard treatment is levothyroxine (thyroxine), a replacement for the hormone your body lacks. Brands at Khasmart include Thyronorm 25 mcg, Thyronorm 50 mcg, Thyronorm 75 mcg, Thyronorm 100 mcg and Thyronorm 125 mcg. The dose is individual, and it is adjusted according to blood tests. Most people need to take it for life.

How to take levothyroxine properly

• Take it on an empty stomach, with a glass of water, at the same time every day. Usually in the morning, 30 to 60 minutes before breakfast, or at bedtime at least three hours after the last meal, as your doctor prefers.
• Keep apart from iron, calcium, antacids, multivitamins, and some other products by at least four hours. They block its absorption. See our guides to iron deficiency and calcium deficiency.
• Do not take it with tea, coffee, soy or high-fibre foods at the same moment. Wait at least 30 to 60 minutes.
• Stay with the same brand if possible. Switching brands can change the effect slightly, so retest after a change.
• Do not skip doses or stop because you feel better. Symptoms return.
• Do not take it for weight loss. In people with normal thyroid function it does not work, and it can damage the heart and bones.

Monitoring

Your doctor will repeat TSH six to eight weeks after starting or changing the dose, then every six to twelve months once stable. Symptoms take weeks to improve, so be patient.

Medicines for hyperthyroidism

Antithyroid medicines such as carbimazole (for example Neo Mercazole) reduce the production of thyroid hormones. Other options are radioactive iodine and surgery. Beta blockers such as propranolol may be added to control the racing heart and tremor.

Important: carbimazole can rarely lower the white blood cell count. If you develop a sore throat, mouth ulcers or fever while taking it, stop the tablet and see a doctor the same day for a blood test. Regular blood tests and follow-up are necessary.

See the thyroid disorders category. If you have a prescription, upload it here.

Pregnancy and thyroid

• Thyroid hormone is vital for the baby’s brain, especially in early pregnancy.
• Women with hypothyroidism often need a higher dose when pregnant. Tell your doctor as soon as you know you are pregnant, and have TSH checked.
• Uncontrolled thyroid problems can lead to miscarriage and complications.
• Plan pregnancy with your doctor. See our guide to pregnancy vitamins and supplements.

Diet and lifestyle

• Use iodised salt, because iodine deficiency still occurs in parts of Pakistan. Do not take iodine or kelp supplements without advice, since too much can also cause problems.
• Eat a balanced diet with protein, vegetables, fruit and whole grains. No special thyroid diet is required.
• Be active: walking helps energy and weight. Read about checking weight and BMI at home.
• Avoid miracle thyroid cures, herbal products and fad diets.
• Do not smoke. It worsens Graves’ eye disease.

When to see a doctor

• Persistent tiredness, weight change, hair loss, constipation or feeling cold, or the opposite: weight loss, palpitations, tremor and heat intolerance.
• A lump or swelling in the neck, difficulty swallowing or breathing, or a hoarse voice that lasts more than two weeks.
• Irregular periods, or difficulty getting pregnant.
• Your symptoms return on treatment.
• Chest pain, a very fast or irregular heartbeat, severe weakness, or confusion. These are emergencies.

Frequently asked questions

Is hypothyroidism curable?

Most cases are permanent, but they are easily controlled with a daily tablet.

Can I take thyroid medicine with milk or tea?

It is better to take it with water. Milk and tea can reduce absorption.

Why does my doctor keep changing my dose?

The dose is adjusted according to TSH, weight, pregnancy and other medicines, until stable.

Will thyroid medicine make me lose weight?

It can bring weight back to your normal range when it was caused by an underactive thyroid, but it is not a weight-loss drug.

Order thyroid medicines on prescription from Khasmart, with delivery across Pakistan.

This article is for general information and is not a substitute for advice from your doctor or endocrinologist. It does not include doses; your doctor decides the medicine and amount. Always follow the directions on the pack or from your doctor.