Hypothyroidism Symptoms: Signs of an Underactive Thyroid and What to Do

"I sleep enough but I'm always tired. I feel cold when others don't. I've gained weight without eating more." Many women in Bangladesh live with these complaints for years, blaming housework, age or stress. Sometimes the real cause is a small gland in the neck: the thyroid.

An underactive thyroid (hypothyroidism) is common, especially in women, and it is very treatable. The NHS notes that with the right treatment, you should be able to live a normal life. The hard part is recognising hypothyroidism symptoms, because they are slow and easy to miss.

What Does the Thyroid Do?

The thyroid is a butterfly-shaped gland at the front of the neck. It makes hormones that control how fast your body uses energy — your metabolism. When it makes too little hormone, many body processes slow down. That is hypothyroidism.

When it makes too much, it is called hyperthyroidism (overactive thyroid) — covered briefly below.

Hypothyroidism Symptoms

The NHS says symptoms may be mild and not easy to notice, and they usually develop slowly and get worse over time.

Common symptoms (NHS):

• Feeling extremely tired (fatigue)
• Feeling cold more than usual
• Putting on weight
• Constipation
• Difficulty concentrating or thinking clearly
• Low mood or depression (see also anxiety symptoms and getting help)
• Dry skin, dry hair or hair loss
• A croaky (hoarse) voice
• Irregular or heavy periods (irregular periods can also be a sign of PCOS)

Why it's often missed

Each of these symptoms has many other possible causes. Tiredness may be blamed on anaemia, weight gain on diet, low mood on stress, and heavy periods on "normal" changes. The NHS advises that because these symptoms are common, it's important to get them checked by a doctor.

Example

Shahana, 38, a school teacher in Barishal, has felt exhausted for a year. Her hair is falling out, her skin is dry, and her periods have become heavy. She has gained 6 kg. Her sister was treated for thyroid disease. A doctor orders a thyroid blood test, which shows an underactive thyroid. After starting treatment and having follow-up tests, her energy slowly returns.

Hypothyroidism vs Hyperthyroidism

The overactive thyroid symptoms above come from the NHS list for hyperthyroidism, which also includes feeling tired all the time and needing to pee more often. Both conditions need a doctor's assessment.

What Causes an Underactive Thyroid?

According to the NHS:

• In the UK, the main cause is an autoimmune condition called Hashimoto's disease, where the immune system attacks the thyroid. It is most common in women and usually starts between ages 30 and 50.
• Other causes include:
  • Another thyroid condition, such as thyroiditis
  • Surgery or radiotherapy to the neck or thyroid
  • Treatment for an overactive thyroid
  • Not getting enough iodine in the diet
  • Certain medicines
• You're more likely to have it if family members have had a thyroid condition.

Iodine

Iodine is needed to make thyroid hormone. The NHS says iodine shortage is rare in the UK; in other countries it may be more relevant. Using iodised salt in cooking (in normal, not excessive, amounts) is a common public-health approach. Do not take iodine supplements without medical advice.

How Is Hypothyroidism Diagnosed?

The NHS says a doctor will:

• Ask about your symptoms
• Ask whether family members have had a thyroid or autoimmune condition, or if you have recently been pregnant
• Examine your neck for a swollen thyroid
• Arrange blood tests for TSH (thyroid-stimulating hormone) and T4 (thyroxine)

The doctor may refer you to a specialist for more tests.

Reading thyroid reports

Each lab prints its own reference range. Generally, in an underactive thyroid, TSH tends to be raised as the body tries to push the thyroid to work harder. But interpretation depends on the full picture — pregnancy, medicines and other illnesses can all affect results. Share the full report with your doctor rather than judging one number.

Treatment: Levothyroxine

The NHS explains:

• An underactive thyroid is usually treated with levothyroxine tablets, which replace the hormone your body cannot make.
• You'll usually need to take them for the rest of your life to prevent symptoms returning.
• You'll have regular blood tests to check you're on the right dose.
• Being on the wrong dose can cause side effects such as feeling or being sick, diarrhoea, headaches or problems sleeping.

Practical tips for taking thyroid medicine

• Take it exactly as prescribed, and at the same time each day
• Follow the leaflet or doctor's advice on whether to take it on an empty stomach and how far apart from other medicines (such as iron or calcium)
• Do not stop because you feel better
• Do not change the dose yourself
• Keep follow-up blood tests on schedule
• Tell your doctor if you become pregnant or plan pregnancy — thyroid treatment often needs review

Risks if Left Untreated

The NHS says an underactive thyroid is not usually serious with the right treatment. But if it's untreated or you're on the wrong dose, there may be increased risk of:

• Heart problems, including coronary heart disease and heart failure (thyroid problems can also affect cholesterol levels)
• Bone problems, including osteoporosis

When to See a Doctor

See a doctor if you:

• Have several symptoms listed above, especially tiredness, feeling cold, weight gain and dry skin together
• Have a family history of thyroid disease
• Notice a swelling at the front of your neck
• Have recently been pregnant and feel persistently low or exhausted
• Are already on thyroid medicine and have new symptoms or side effects

Seek urgent care for a neck swelling that causes difficulty breathing or swallowing.

Frequently Asked Questions

What are the first signs of hypothyroidism?

Often tiredness, feeling cold, weight gain and constipation. They develop slowly, so many people don't notice at first.

Is hypothyroidism common in women?

Yes. The NHS notes Hashimoto's disease, its main cause in the UK, is most common in women and usually starts between 30 and 50.

Can hypothyroidism be cured?

It's usually managed long-term with levothyroxine. With the right dose, most people live normally.

Which test shows thyroid problems?

Blood tests for TSH and T4 are the main tests, according to the NHS.

Can I stop levothyroxine if I feel better?

No. The NHS says you usually need it for life to prevent symptoms returning. Talk to your doctor before any change.

Does thyroid cause weight gain?

An underactive thyroid can cause weight gain. Treatment may help, along with healthy eating and activity.

Discuss Your Thyroid Report on ShifaMate

If you have symptoms or a thyroid test report, you can consult a verified doctor through ShifaMate. Upload a clear photo of your TSH/T4 report, list your symptoms and current medicines, and mention pregnancy or family history. The doctor can explain your results, advise on next steps, and issue a digital prescription when clinically appropriate. You can also browse ShifaMate doctors.

References

• NHS. Underactive thyroid (hypothyroidism) — symptoms
• NHS. Underactive thyroid — treatment
• NHS. Overactive thyroid (hyperthyroidism) — symptoms

This article is for general information and does not replace advice from a qualified doctor.