Can thyroid issues cause hair loss?

Reviewed by our clinical team

Your thyroid is a small gland located in your neck which produces hormones that affect your body in many ways, including maintaining your heart rate and body temperature. 

Occasionally, your thyroid can misbehave and affect your health, leading to a range of conditions. But can thyroid issues cause hair loss?

What is the thyroid? 

The thyroid is a small, butterfly-shaped gland located at the front of the neck, just in front of your windpipe. 

It produces a number of hormones, triiodothyronine (T3) and tetraiodothyronine (T4), which affect your metabolism and growth, and calcitonin, which regulates calcium levels to help maintain healthy bones and muscles.

There are two conditions that can affect your thyroid gland and lead to either an excessive amount of hormones (hyperthyroidism) or not enough (hypothyroidism). 

Types of thyroid problems

The two main issues that can affect the thyroid are an overactive thyroid (hyperthyroidism) and underactive thyroid (hypothyroidism).

Hyperthyroidism (overactive)

Hyperthyroidism is the medical term for an overactive thyroid, where your thyroid produces too much T3, T4, and Calcitonin. Hyperthyroidism is 10 times more common in women than men and usually occurs between the ages of 20 and 40.

Common symptoms of an overactive thyroid include irritability, palpitations, sweating, diarrhoea and weight loss. Some people notice a swelling of the neck just above the Adam's apple. This is known as a goitre.

Depending on the cause, different treatments may be advised; this could be tablets, radioactive iodine or surgery.

Hypothyroidism (underactive)

Hypothyroidism is the medical term for when your thyroid does not produce enough hormones. This is usually because your immune system attacks it accidentally, or because the thyroid has been damaged by other medical treatments or cancer. 

You might experience tiredness, weight gain, depression, or changes in the texture of your hair and skin or period pattern with an underactive thyroid. There’s no way to prevent an underactive thyroid, but it is easy to treat. 

Symptoms of thyroid problems

Despite the similarity of the names, hyperthyroidism and hypothyroidism can affect your body in very different ways. If left untreated, you might become unwell, so it’s important to know what to look for.

Overactive thyroid symptoms

When your thyroid is producing too many hormones, you can experience a range of symptoms including:

• Weight loss
• Swelling in your neck (goitre)
• An irregular and/or unusually fast heart rate (palpitations)
• Nervousness and anxiety
• Mood swings and irritability
• Insomnia
• Constant tiredness and weakness
• Heat sensitivity
• Twitching or trembling
• Diarrhoea
• Bulging eyes
• Infrequent periods

These symptoms don’t mean that you have hyperthyroidism, but if you notice several at once or have been experiencing them for a long time, you should pay a visit to your GP. 

Underactive thyroid symptoms

Symptoms of an underactive thyroid (hypothyroidism) include:

• Tiredness
• Weight gain
• Depression
• Dry skin and hair
• Muscle aches
• Sensitivity to the cold
• Heavier periods

Again, these symptoms aren’t always an indicator of thyroid issues, but you should speak to a doctor if you’re concerned.

The only way to know for certain if you have an underactive or overactive thyroid is to undergo a thyroid function blood test, which your doctor can organise for you.

Do thyroid problems cause hair loss? 

Having a thyroid condition can be worrying and you might be concerned about possible long term issues or ongoing problems.

Hair loss is a very common symptom of many illnesses, but the severity and location can depend on a range of factors. 

Very severe or prolonged thyroid issues can eventually lead to hair loss, usually across the scalp rather than in a roundish patch (alopecia areata), but this isn’t a common or early symptom. Hair loss is far more likely with hypothyroidism, as it can cause your hair to become brittle.

If the problem is diagnosed and treated early, hair loss can be prevented. It’s very unlikely that short-term thyroid problems or mild hypo or hyperthyroidism will cause hair loss.

So, hair loss isn’t very common with thyroid conditions, but it can happen if the condition isn’t treated. This is why it is crucial to know what the symptoms look like and to speak to your doctor if you’re worried.

Will hair loss from a thyroid condition grow back?

Is thyroid hair loss reversible? Yes, usually. If you do experience hair loss with thyroid problems, it usually grows back once the condition has been treated, although the texture of your hair might be different.

Does thyroid medication cause hair loss? 

Thyroid problems themselves don’t cause hair loss in most cases. Medications designed to treat hyperthyroidism and hypothyroidism can lead to hair loss, but this is also very rare.

Two of the most common medications for treating hyperthyroidism, carbimazole and propylthiouracil, can lead to hair loss in some cases. Due to the long life cycle of hair, however, it can be difficult to identify whether it is the condition itself or the treatment that is causing the hair loss.

If you’re concerned about losing your hair during thyroid treatment, you should discuss it with your doctor, to see if your treatment can be changed.

Remember, hypothyroidism and hyperthyroidism can seriously impact your health and wellbeing, so it’s important to see your GP if you think you might have a thyroid problem.

How to deal with thyroid related hair loss? 

If you do experience hair loss, either due to a thyroid condition or the medication used to treat it, there are a few things you can do.

Thyroid hair loss treatment 

Once your thyroid issue has been identified and treated, your hair should return to normal within a few months. If the treatment itself is causing hair loss, please discuss this with your GP to see if your treatment can be changed.

Natural remedies for thyroid hair loss

If you’re already being treated for thyroid problems, there are some other ways you can naturally support your hair and encourage regrowth.

Ferritin/iron

Ferritin is a blood protein that stores iron, and when there isn’t enough iron in your blood, your body will take it from non-essential tissue, such as your hair follicles, leading to hair loss. So sometimes low iron can be a cause of hair loss. 

You can boost your iron levels by eating iron-rich foods like red meat or fish, spinach and other leafy greens, lentils, and kidney beans.

Vitamins

In some cases, hair loss can be due to a lack of crucial vitamins in the body, including:

• Biotin
• Selenium
• Niacin
• Vitamin C
• Iron
• Zinc

You can buy vitamin supplements to increase the amount of these vitamins in your body. However, it’s important to know that if your hair loss is caused by a thyroid condition, additional vitamins alone will not help, and the condition should be treated with the right medication.

Nonetheless, when taken together with other treatments and with the support of your doctor, hair loss vitamin supplements might help keep your hair strong and healthy. You can learn more about hair loss vitamins here.

Look after your hair

Hair loss usually occurs alongside thyroid issues because the hormonal imbalance has led to your hair becoming brittle. In these cases, it’s important to make sure you look after your hair to avoid making things worse. You should:

Avoid using hair dyes, harsh shampoos, perming products, and heat sources like hair dryers or straighteners

Adopt a looser hairstyle and avoid hairstyles that pull on your hair like tight buns and ponytails

Avoid hair extensions

By not putting additional pressure on your hair follicles, you can minimise the amount of damage, and make it easier for regrowth to occur.

Summary

Thyroid conditions like hypothyroidism and hyperthyroidism can be distressing enough without adding hair loss to the mix. Although losing your hair can be worrying, it’s important to talk to a doctor to identify the cause. They may want to carry out a blood test. 

Once the condition is treated, your hair should recover. Your doctor can also discuss the problem with you to ensure you feel confident and as relaxed as possible.

References

https://www.nhs.uk/conditions/overactive-thyroid-hyperthyroidism/
https://www.nhs.uk/conditions/underactive-thyroid-hypothyroidism/
https://thyroiduk.org/if-you-are-hypothyroid/importance-of-iron-and-ferritin-in-hypothyroidism/
https://www.nhs.uk/conditions/hair-loss/