These are the main issues to consider when losing hair:

1. Hypothyroid. Do a full thyroid screen including reverse T3 and autoimmune antibodies; not just TSH and T4 levels. Read about thyroid illness on this A-Z and start maybe with the free basal temperature test on the shop. If it is because of a drop in oestrogen, progesterone or thyroxine (in hypothyroid), once you start to get those controlled better, it will likely thicken up again. This usually looks like thinning along the parting. A big clue that it is hypothyroid is losing the outer third of your eyebrows too.

2. Gluten illness: autoimmune attack on the follicles is a known problem and gluten is a common denominator in many autoimmune processes. Have a look here, for example, and here. Read more about gluten illness here on this site.

3. Nutritional deficiency, especially of zinc, Vit C, B vits, particularly biotin. Of course, the nutritional deficiency is sometimes secondary to the gluten causing malabsorption so gluten can be the real key. You can see more and how to test nutrients properly here. And a good supportive hair supplement might be this hair, skin and nails complex.

4. Anaemia, especially of iron, because it lowers oxygenation and therefore blood flow and nutrients to extremities, including your scalp. If your blood pressure is lower than 120/80, that will also cause poor blood flow – if your nose, hands and feet feel colder than they should, your nail beds look pale and you have fungal toenails – they are all clues of poor blood flow. Tip: Do not necessarily believe female ferritin levels of less than 70, especially if your ESR inflammation marker is high. And, again, anaemia is one of the key triggers clinically for investigating coeliac disease and non-coeliac gluten sensitivity. You can get a really good, proper, anaemia test here.

5.  Upset androgen (male hormone) levels, especially of testosterone – too little in men, or too much DHT type testosterone, and too much in women. PCOS is actually the most common cause of hair loss in women. This usually looks like hair receding from the forehead or from the top of the crown. Studies suggest massaging your scalp and using shampoos made with rosemary and grapeseed extract really helps because it seems to block the action of the DHT on hair follicles. You can do a simple testosterone check or, preferably, a full female or male hormone profile. You can see all the hormone tests here: Women’s and Men’s .

Those are the first things I would investigate from a biochemical point of view anyway.

Of course, stress is a major factor too and an adrenal check would be good advice if you are feeling like you don’t cope as well with life as well as you used to. See the factsheet on Adrenal Fatigue.

The good news is that it is usually reversible or at least significantly improveable. You can get lots more info and support from Alopecia UK and I thought their FAQ was particularly good.

Hope that helps. Remember: it is very probably temporary so try not to worry.