Thyroid disease can occur when your thyroid gland either doesn’t produce enough, or produces too much of certain hormones. Hypothyroidism – or an underactive thyroid – can cause many symptoms ranging from weight gain to fatigue which are linked to reduction in metabolism.
On the other end, hyperthyroidism, an overactive thyroid, may cause anything from weight loss to nervousness. Both conditions may take time to develop and show symptoms, and it is important to take appropriate tests and consult with your GP if you suspect you suffer from these. It can cause dry, brittle or thinning hair – however the way both conditions affect your hair – is different.
Read on and learn what you can do if your thyroid disease is affecting your hair.
Biology of thyroid hair loss
It starts with the brain. Thyroid stimulating hormone (TSH) is produced by the pituitary gland located at the base of your brain. TSH stimulates the thyroid gland to produce thyroxine (T4) and triiodothyronine (T3).
When it comes to hair growth, it is the T4 that stimulates the hair matrix to produce and multiply keratinocytes.
(Keratinocytes is a cell type in the outer layer of the skin. In hair growth, keratinocytes play an especially important role, since they participate in forming hair follicles by regulating stem cell production in the follicle that ultimately become to be your hair strands.)
In addition, both T3 and T4 are responsible for slowing down apoptosis – the death of keratinocyte cells. Therefore these two thyroid hormones further support the correct functioning of the hair follicle and your hair growth.
Hypothyroidism
Hypothyroidism is underactive thyroid that makes insufficient amounts of T3 and T4. The link to hair loss and thinning is straightforward: as the body doesn’t produce enough of these hormones to promote proliferation of keratinocytes, it reduces the function of the hair follicle to grow hair.
Brittle, thin and dull hair is common amongst the sufferers of hypothyroidism. Hashimoto's disease is an autoimmune disorder that can cause hypothyroidism, or under-active thyroid. With Hashimoto's, immune system attacks thyroid gland. As a result, thyroid gland is damaged and can't make enough thyroid hormones.
Hyperthyroidism
Hyperthyroidism occurs when thyroid gland produces too much of the hormone thyroxine. It can accelerate your body's metabolism, causing unintentional weight loss and a rapid or irregular heartbeat. Graves' disease is an autoimmune disorder that causes hyperthyroidism, or an overactive thyroid.
With this disease, the immune system attacks the thyroid and causes it to make more thyroid hormone than your body needs. Carbimazole and propylthiouracil are antithyroid drugs that may, in rare cases, lead to hair loss. They artificially reduce T3 and T4 hormones which impacts hair growth.
However, a clear link between hyperactive thyroid gland and hair loss is less clear. One study has shown that overdose of levothyroxine, a drug for treating hypothyroidism to compensate for production of TSH causes diffuse hair loss and hair thinning.
However the conclusion was unclear if the drug overdose is what caused it or further development of the hypothyroidism and resistance to treatment. More research in this area is necessary.
Treatment options for thyroid hair loss
Treating thyroid-related hair loss requires treating the underlying thyroid problem which is the root cause for the hair thinning.
Levothyroxine and hair loss
For an under-active thyroid, a doctor will usually prescribe a synthetic hormone containing levothyroxine. Levothyroxine is taken to replace the missing thyroid hormone thyroxine (T4). With normal thyroid functioning, it adjusts and regulates how much thyroid hormone is being pumped out hour by hour and minute by minute.
When you take thyroid medication, like levothyroxine, you are replacing this complex and delicate system with your daily dose of thyroid hormone in a single dose that you take once per day.
Such spike can affect your hair growth as a result of spiking T4 rather than its slow and gradual production and release. Therefore it is important to ensure that you are taking the required dose of the drug and not accidentally take too much.
In this article we cover how to tackle hair loss as a symptom of thyroid problems – however bear in mind that the root cause needs to be treated as a priority: the symptoms can only be alleviated to a limited extent.
The best approach would be to get your blood tested and understand what is the optimal level of T3 / T4 hormones. Your hair health is likely to return to normal as a result of getting your hormones in balance and over a course of time.
Meanwhile, home remedies and lifestyle changes are available for sufferers of both conditions. Those can take a few weeks or months to work so it is important to approach it with a curious mind and willingness to learn about what works for your body, as opposed to expecting overnight results.
Thyroid hair thinning and anti-inflammatory diet
As a general rule, eating a balanced diet can help to promote growth and improve the condition of your hair. This also include autoimmune disorders, which under-active thyroid is.
Reduction of the inflammation in your body as a result of healthy gut microflora improves absorption of the nutrients from your body and can help stop or slow down your immune system attacking itself, which includes your thyroid gland, too. A healthful and balanced diet is one that contains protein, fresh fruits, vegetables, grains, and a moderate amount of fat.
Ferritin and hair loss
Ferritin is a protein that combines with iron and is used by your body as a main form of iron storage. If you are losing iron through sweat, shedding intestinal cells, and blood loss (e.g. heavy bleeding during menstruation), the body can maintain its iron levels by drawing on its stores until they are all used up.
When this happens, the iron levels can no longer be maintained at their normal levels and will start to fall. Even though iron is an essential metal in human metabolism, it is highly toxic to cells and tissues if present in elevated levels. Therefore it's also important to understand if combined with your thyroid condition you actually are low on iron or ferritin before taking on any supplementation.
Studies suggest that people with low levels of ferritin may experience hair loss and thinning, especially those suffering from female pattern hair loss and male pattern hair loss. When there isn’t enough iron in the diet, the body takes ferritin stored in the non-essential tissue – like that in your hair bulb – and gives it to essential tissue – such as your heart.
Because your hair bulb is where all your hair cells are produced, this "leeching" of ferritin can cause your hair to shed before it reaches its maximum length.
The small amount of ferritin that is released and circulates in the blood is a reflection of the total amount of iron stored in the body. A quick boost of ferritin is available through eating lean red meat or fish; or vegetarian and vegan options include iron-rich foods like kale, spinach and other dark leafy greens, also lentils, red kidney beans and pumpkin seeds that need to be combined with vitamin C-rich foods to improve absorbency of iron into the bloodstream.
Iron, hypothyroidism and hair loss
Underactive thyroid can lead your stomach produce less hydrochloric acid, or none at all (as can anti-acid medications) – which in turn, can lead to poor iron absorption and therefore iron deficiency and the associated hair growth problems with that.
Lower body temperature associated with hypothyroidism can also cause fewer red blood cells to be produced by the temperature-sensitive bone marrow.
Low iron/ferritin levels are a particular problem for those with hypothyroidism for several reasons:
- Normal thyroid hormone metabolism depends on adequate supplies of iron, together with iodine, selenium and zinc. To support your thyroid function it's important to ensure adequate intake of those nutrients.
- Symptoms of anaemia mimic those of hypothyroidism which may lead you to believe you are not taking enough thyroid medication or that the thyroid medication is not working. Symptoms such as fatigue, brain fog and hair loss – are signs of hypothyroidism but it is also caused by low iron levels Patients can easily believe that hair loss is a remaining sign of hypothyroidism, without realising they may have low levels of iron/ferritin instead.
- Low iron levels may result in the thyroid peroxidase enzyme, which is iron-dependent, becoming less active and as a result, reducing production of thyroid hormones.
Iodine
The body uses iodine to make thyroid hormones, and therefore too much or too little of iodine may affect your thyroid. People with autoimmune thyroid disorders need to be careful around their iodine intake. Adults need 150mcg of iodine per day.
Generally, insufficient amounts of iodine alone would not be the reason for hair loss, but inadequate amounts of iodine amongst many other factors that create a misbalance of thyroid hormones can well lead to hair loss, hair thinning and brittle hair. Therefore you wouldn't have an iodine problem, but a thyroid problem that impacts your hair health, where iodine levels could contribute to the overarching thyroid dysfunction.
Consider taking a test to understand your levels of iodine and consult with your doctor on your individual iodine requirements. Mountainous areas, such as the Himalayas, Alps, and Andes regions, and river valleys prone to flooding, especially in the South and Southeast Asia, are among the most iodine-deficient regions in the world. If you live in the area with low iodine, fortified products can help to compensate for the lack.
Pregnant and breastfeeding women have a higher requirements for iodine – where RDA is 219mcg and 290mcg respectively. Therefore to ensure correct thyroid functioning you may need to consider your iodine intake if this situation applies to you.
Postnatal hair loss (also known as postpartum alopecia) is common amongst 90% of women where 60-70% have noticeable hair loss. Pregnancy can cause worsening of an already existing thyroid dysfunction that could lead to worse condition of your hair. Therefore hair loss is a symptom of potentially a more pressing problem behind it – so speaking with your physician / GP about your concerns becomes ever more important.
Vitamins
Staying on top of taking your required supplements is important, since a lot of the foods we consume don’t actually contain as many vitamins and nutrients. They are grown in the artificial conditions and with addition of pesticides that reduce nutritional value of the said foods.
Ensuring to get sufficient B-vitamins, zinc, vitamins C becomes crucially important for those already suffering from thyroid dysfunction. The idea is to bring your body in balance as much as possible.
Hair styles and root support
Ensure to treat your hair gently. Avoid using harsh colouring products and shampoos, perms and heating tools. Refrain from wearing hairstyles that pull on the hair (such as a tight bun or pony tail) and embrace the braid.
This causes less impact on the follicle, thus helping it recover quicker. The same logic applies if you wear hair extensions – you need to reduce the unnecessary pull on the hair root that comes from wearing extensions.
Blood flow and hair regrowth
Losing your hair can be distressing, but if it is caused by thyroid disease it is most likely reversible. To help you on the journey towards healthy hair, it is key to focus on blood flow to scalp as it directly impacts hair follicle.
If one of the symptoms of thyroid gland you are experiencing is hair loss, scalp stimulation becomes even more important as your body naturally produces less hormones to stimulate your hair follicles, so don’t skip on additional support to your scalp.
Sources
Thyroid Hormones Directly Alter Human Hair Follicle Functions: Anagen Prolongation and Stimulation of Both Hair Matrix Keratinocyte Proliferation
and Hair Pigmentation, The Journal of Clinical Endocrinology and Metabolism, (1)
Keratinocytes regulate the function of melanocytes, (2)
The effects of thyroxine on hair growth in the dog, (3)
Diffuse scalp hair loss due to levothyroxine overdose, (4)
Iron Plays a Certain Role in Patterned Hair Loss, (5)
Keratinocyte Growth Factor Increases Hair Follicle Survival Following Cytotoxic Insult, (6)
Iodine intake and status during pregnancy and lactation before and after government initiatives to improve iodine status, in Palmerston North, New Zealand: a pilot study (7)
Molecular mechanisms involved in intestinal iron absorption (8)
The Importance of Iron and Ferritin in Hypothyroidism (9)
