In the first of a two-part series on thyroid conditions, here is some information about the symptoms and treatment of an underactive thyroid.
An underactive thyroid (hypothyroidism) is when your thyroid gland does not produce enough of the hormone thyroxine (also called T4).
An underactive thyroid is caused by the immune system attacking the thyroid gland and damaging it, or by the damage that occurs as a result of treatments for thyroid cancer. An underactive thyroid cannot be prevented.
Both men and women can have an underactive thyroid, although it is more common in women. In the UK, it affects 15 in every 1,000 women and 1 in 1,000 men.
Symptoms of an underactive thyroid
Many symptoms of an underactive thyroid are the same as those of other conditions – it can be easy to confuse them for something else. Symptoms usually develop slowly, and you may not realise you have a medical problem for several years.
Typical symptoms include:
- weight gain
- feeling cold
- Slow thoughts and movements
- muscle aches, muscle cramps and weakness
- dry and scaly skin
- brittle hair and nails
Older people with an underactive thyroid may develop memory problems and depression.
Thyroid function test
If you have any of these symptoms, see your GP and ask to be tested for an underactive thyroid.
The test, called a thyroid function test, looks at levels of thyroid-stimulating hormone (TSH) and thyroxine (T4) in the blood.
A high level of TSH and a low level of T4 in the blood could mean you have an underactive thyroid.
If your test results show raised TSH but normal T4, you may be at risk of developing an underactive thyroid in the future.
Your GP may recommend that you have a repeat blood test every so often to see whether you eventually develop an underactive thyroid.
Treating an underactive thyroid
Treatment for an underactive thyroid involves taking daily hormone replacement tablets, called levothyroxine, to raise your thyroxine levels. You will usually need treatment for the rest of your life.
However, with proper treatment, you should be able to lead a normal, healthy life.
You’ll initially have regular blood tests until the correct dose of levothyroxine is reached. This can take a little while to get right.
You may start on a low dose of levothyroxine, which may be increased gradually, depending on how your body responds. Some people start to feel better soon after beginning treatment. Others do not notice an improvement in their symptoms for several months.
Once you’re taking the correct dose, you will usually have a blood test once a year to monitor your hormone levels.
If blood tests suggest you may have an underactive thyroid, but you do not have any symptoms or they are very mild, you may not need any treatment. In these cases, your GP will usually monitor your hormone levels every few months and prescribe levothyroxine if you develop symptoms.
If you’re prescribed levothyroxine, you should take one tablet at the same time every day. It’s usually recommended that you take the tablets in the morning, although some people prefer to take them at night.
The effectiveness of the tablets can be altered by other medications, supplements or foods, so they should be swallowed with water on an empty stomach, and you should avoid eating for 30 minutes afterwards.
If you forget to take a dose, take it as soon as you remember if this is within a few hours of your usual time. If you don’t remember until later than this, skip the dose and take the next dose at the usual time unless advised otherwise by your doctor.
Tell your doctor if you develop new symptoms while taking levothyroxine. You should also inform your doctor if your symptoms do not improve or get worse.
While levothyroxine is the recommended treatment for an underactive thyroid some people may prefer to take alternative treatments.
There is no hard medical evidence that alternative treatments work to manage an underactive thyroid.
But if individuals are looking for alternative treatments they can seek advice from a herbalist, who may suggest taking sea vegetables, such as ‘bladderwrack capsules’, which are rich in iodine and are said to have a regulating effect on the thyroid.
The minerals selenium and zinc are required at the right levels for healthy thyroid function, so taking a multivitamin and mineral supplement is an option.
Other nutrients that are believed to be important for thyroid health include the minerals calcium and magnesium.
If you are looking at alternative therapies to manage your underactive thyroid you should always talk to your doctor first.
If an underactive thyroid is not treated
It is unlikely that you would experience many of the later symptoms of an underactive thyroid because the condition is often identified before more serious symptoms appear.
Later symptoms of an underactive thyroid include:
- a low-pitched and hoarse voice
- a puffy-looking face
- thinned or partly missing eyebrows
- a slow heart rate
- hearing loss
For further information, visit The British Thyroid Foundation, which is a charity dedicated to supporting people with thyroid disorders. Visit: