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What illnesses cause hair loss?

What illnesses cause hair loss?

Hair loss can be caused by a range of factors including your genetics and certain skin conditions. In this article we look at the illnesses, health conditions and lifestyle changes that could potentially cause hair loss and how hair loss could be a sign of an illness or underlying condition.

Usually hair loss is nothing to worry about, however if you are concerned about the amount of hair you’re losing you should speak to your GP, read more of our hair loss advice and see what treatments could be suitable for you.

Hormonal imbalance hair loss

Hormonal imbalances can cause hair loss in men and women of all ages. Hormonal changes may be part of the natural ageing process, such as the menopause. The menopause may affect hair growth and thickness due to a drop in the levels of oestrogen and progesterone. These hormones help your hair to grow faster while staying on your head for longer.

The male hormone testosterone plays its part in male pattern baldness. Mainly influenced by genetics, male pattern baldness is caused by testosterone being converted to DHT in the body. DHT causes hair to fall out and can halt hair production, there are treatments available that can promote hair regrowth.

Hair loss during pregnancy

During pregnancy some people’s hair gets thicker and some may experience hair loss. Hair loss during pregnancy could be a sign of a vitamin deficiency or another condition. If you’re worried about the amount of hair you’re losing you can always talk to your midwife or GP.

When you’re pregnant you should try to eat a balanced healthy diet as much as possible, and take supplements formulated for pregnancy which can help keep you and your baby healthy.

Hair loss after you’ve had your baby is more common, as this type is triggered by hormonal changes such as child birth. Postpartum hair loss (Telogen Effluvium) could mean you lose up to 300 hairs a day compared to the 100 lost by the average person. This increase is due to your hair transitioning from the resting phase to the falling out phase a lot quicker than it normally would. You may not experience Telogen Effluvium until two to four months after the birth of your baby.

Medications that cause hair loss

Most medicines have side effects to some extent which is why it’s important to read the patient information leaflet carefully before taking any medication. With some treatments such as cancer treatment, hair loss can be expected but there are other medications that can cause hair loss. Hair loss can be caused by taking medications for conditions such as heart problems, high blood pressure and arthritis.

If you think your medication is causing hair loss you should talk to your GP. They may suggest hair loss treatments and lifestyle changes such as diet or vitamins.

Thyroid issues and hair loss

Thyroid problems that are prolonged or severe may eventually lead to hair loss, however it’s not a common or early symptom of an overactive or underactive thyroid. Hair loss may be more likely if you have an underactive thyroid as this can make your hair dry and brittle, however early treatment and care can help prevent any hair loss. If you think you have a thyroid issue you should speak to your GP.

Alopecia areata

Alopecia areata can affect all genders, it causes hair to fall out in round or oval patches on the head and on other areas. It’s thought to be an autoimmune condition, where the body’s immune system attacks your hair follicles.

There are treatments available, men and women can use Minoxidil also known as Regaine. This solution stimulates hair follicles and regrowth, it’s available without a prescription. Finasteride, also known as Propecia, is a prescription treatment that only men can use to stop hair loss and stimulate growth.

Autoimmune disease and hair loss

There are other autoimmune conditions besides alopecia areata that can cause hair loss. Lupus is a long-term condition that causes inflammation in the body resulting in joint pain and extreme tiredness. It can also cause scarring alopecia where lesions appear on the scalp and lead to hair loss. If you have Lupus you should speak to your doctor as soon as possible if you are experiencing any type of hair loss.

Nutrient deficiency and hair loss

It’s important to eat a healthy, balanced diet for our overall well being, and to help you avoid any nutrient deficiencies. Certain nutrients can help to support hair growth and keep it healthy. Not getting enough of these essential nutrients can lead to deficiencies which may lead to dry, brittle hair or hair loss.

Trauma and hair loss

Temporary hair loss can occur after times of physical or emotional trauma. Stressful life events may cause people to experience temporary thinning of the hair. This can occur months after the physical or emotional shock. If you have or are experiencing trauma or distress you can reach out to family, friends and your GP. You don’t have to go through anything alone, support is available. 

Stress induced hair loss

We all experience stress from time to time, and it can affect us all in different ways. Stress and stressful situations can cause symptoms such as headaches, heartburn and hair loss. Stress induced hair loss tends to be temporary, and the most common type of hair loss caused by stress is telogen effluvium. This is where the growing phase in the hair life cycle is cut short and because of this more hairs will start to fall out than they normally would.

Stress induced hair loss can occur sometime after a stressful event or period of stress, so you may not realise what your body is reacting to. If you’re feeling stressed a lot of the time, speak to your GP and find ways to manage your stress.

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Hair loss can be caused by a range of situations from nutrient deficiencies to major life events. If you’re experiencing hair loss, you’re not alone and help is available. There’s hair loss treatments to help look after the hair you have and stop any future hair loss. If you would like more support with hair loss you can speak to your GP.



Authors and editors

Reviewed and updated by: Our clinical team Date reviewed: 15-02-2024