Daily Health

Hair Thinning Causes and Treatments: What You Need to Know

No one wakes up, looks in the mirror, and is overjoyed to see their hair is thinning. But a change to your hairline doesn't have to mean the end of the world — and you don't have to resign yourself to a lifetime of hats either.

Experiencing hair loss and thinning hair can be an emotionally taxing experience. Since hair can play a major role in self-image and confidence, noticing less of it where you once had plenty can be jarring. However, it may be comforting to know that hair loss is a normal part of aging for most people. While the degree of hair thinning or hair loss will vary from one person to the next, we can all expect some degree of hair thinning at some point so it's worth getting familiar with the basics of hair loss.

So, what’s just normal thinning and what might be cause for concern or a sign of an underlying health issue? We'll go over the most common thinning hair causes, as well as the range of treatments you can explore if you'd like to regain your glorious former mane, or put a pause on thinning before the situation gets worse.


Your body is a complex, interconnected system, so just like any other health issue, your hair can be affected by a wide range of factors. Thinning can be a sign of an underlying health problem, an element of your lifestyle, or a combination of factors.

According to the Canadian Hair Loss Foundation, there are over 100 potential causes of hair loss. However, since many of these are quite rare, your thinning hair is most likely caused by one of the leading causes we'll take a look at here. Narrowing down the cause of your hair thinning or hair loss is an important first step in determining which treatment option is right for you.

Male or female pattern hair loss

Male pattern baldness and female pattern baldness both fall under the term androgenic alopecia. It’s a common cause of hair loss, although it impacts people with male hormones and people with female hormones differently. There is also a genetic component to this type of hair loss and thinning hair.

In people with male hormones, hair thinning typically begins at the hairline and temples and progressively proceeds toward the back of the head. Female pattern baldness tends to occur at the crown of the head rather than the hairline. This type of hair loss becomes more common with age, and in females, it is more likely to occur after menopause.

Male pattern hair loss can be assessed using a system of c called the Norwood Scale, a classification system that can help to diagnose the progression of male pattern baldness. We cover the 7 stages of hair loss classified by the Norwood Scale in our Hair Loss 101 guide. 

Typically when a healthcare professional examines your hair loss using the Norwood scale, anything at stage 3 or later can be considered male pattern baldness. This is when the receding hairline becomes more noticeable and forms a prominent “M” shape. 


Diet can also contribute to thinning hair since a range of nutrients are required in order for hair follicles to produce hair. Vitamin D, iron, zinc, folic acid, selenium, protein, and omega 3 and 6 fatty acids all play a part in healthy hair growth. Nutritional deficiencies are common in the general population, especially for iron. However, the links between diet and hair thinning are complex, so it's not typically a simple matter of popping a multivitamin and seeing results.

A 2017 review of the available data in the Journal of Dermatology Practical and Conceptual, found that while nutrient deficiencies may result in hair loss, these deficiencies may arise from a range of factors in each patient and the best course of action to correct deficiencies may vary from one individual to the next. The ideal range of micronutrients to correct hair loss is also unclear.

Disordered eating patterns can also contribute to thinning hair. Eating disorders such as anorexia nervosa and bulimia leave the body depleted of the essential nutrients required for healthy hair follicles. Dramatic weight loss over a short period of time may similarly lead to hair thinning.

There is a common misconception that the supplement creatine causes hair loss, but at this time, there is no conclusive evidence that this is the case.


Hair thinning from stress is called telogen effluvium, and it occurs as a result of a sustained level of stress hormones in the body. The good news about this type of hair thinning is that when a situation causing stress is resolved, hair may return to its normal thickness. 


Pregnancy can impact hair loss as well, but this is usually temporary. Many people find that their hair seems thicker during pregnancy, but after giving birth it goes through a period of thinning. This type of thinning hair is connected to the hormonal changes in the body associated with pregnancy, and is a component of telogen effluvium as well. 

Hairstyling and treatments

Many hair treatments can be harsh and lead to hair thinning. Treatments such as bleaching, perming, or relaxing hair compromise the integrity of the hair shaft making it more likely to break off. So while the problem may not be at the level of the follicle, hair can feel much thinner overall after too many of these treatments.

Hairstyling can also be responsible for a type of hair loss called traction alopecia. This type of hair thinning or loss results from hairstyles that pull the hair tightly at the root, such as tight ponytails or braids.

Autoimmune diseases

Hair loss can be one of the first signs that people notice when they are suffering from an autoimmune disease. Alopecia areata is the most common autoimmune disease that causes hair loss in patches, but others such as Crohn’s disease, lupus, and thyroid disease can also cause hair loss.


A wide range of medications can lead to temporary or long-term hair loss, so if you're taking any kind of medication, discuss it with your healthcare practitioner to determine if it may be causing the side effect of hair loss.

Common types of medication that can have this unwanted effect are some antidepressants, acne medications, and medications for high blood pressure. Going off of hormonal birth control can also cause some to experience hair thinning.

Chemotherapy and radiation are also well known for causing hair loss in people for the duration of the treatment, but luckily hair typically grows back once treatment is finished. Sometimes, this new growth may be thinner than the hair was previously.

Skin disorders or infections

It is possible for fungal or bacterial skin disorders or infections affecting the scalp to interfere with normal hair growth, leading to hair loss for the duration of the infection. 

Thinning hair treatment

How to stop thinning hair in a patient will depend on the underlying cause of the hair loss. If your healthcare provider is able to identify a reversible cause such as an infection, medication or hormonal cause, they may be able to suggest treatment. Luckily, there are many treatments available that are largely safe and effective. While it's not always possible to restore hair to 100% of its former thickness, interventions can improve hair loss for many people.


Minoxidil is the active ingredient in the popular OTC hair loss treatment, Rogaine. While it is available without a prescription, it's always a good idea to discuss it with a healthcare practitioner before starting treatment. It can be effective in treating many of the most common thinning hair causes, including male and female pattern baldness and alopecia areata.

It's not entirely clear how minoxidil works. The drug was initially used to treat hypertension, and increased hair growth was noticed as a side effect. It’s worth noting that minoxidil works as long as it is being used, but hair loss will likely resume when use is discontinued. Minoxidil can also be used in combination with finasteride for improved results.

While the risk of side effects is low, you may experience some itching at the application site. If you experience any of these more serious side effects, contact your doctor:

  • Severe irritation
  • Chest pain
  • Flushing
  • Light-headedness
  • Headache, dizziness, or confusion


Finasteride is one of the most common and widely used hair loss medications, along with minoxidil. Also known by the brand name Propecia, it's taken orally, and can be used in the treatment of male pattern baldness. Unlike minoxidil, it is available only by prescription. The results of finasteride only last as long as it is actively being taken.

Potential side effects of finasteride include:

  • Depression and anxiety
  • Erectile dysfunction
  • Decreased sex drive
  • Rashes
  • Breast enlargement and tenderness

These may disappear after a few days or weeks on the medication. If you experience any of these more serious side effects, contact a doctor immediately:

  • Suicidal ideation
  • Nipple discharge
  • Swelling of lips, tongue, throat, or face
  • Lumps or pain in chest area


Spironolactone is a drug typically prescribed for the treatment of high blood pressure and heart failure. Because it has an anti-testosterone effect, it is also occasionally prescribed to treat acne, and can be used by those experiencing female pattern baldness.

Since it also treats high blood pressure, it’s possible for spironolactone to cause low blood pressure if taken for hair loss. Potential side effects include:

  • Drowsiness
  • Diarrhea
  • Headache
  • Breast tenderness
  • Low sex drive

A more serious side effect is high potassium levels. Call your doctor immediately if you experience these symptoms of high potassium levels:

  • Muscle fatigue
  • Weakness
  • Irregular heartbeat
  • Nausea
  • Paralysis 


Corticosteroids can be used to treat autoimmune diseases, and are sometimes prescribed for those suffering from alopecia areata or scarring alopecia. This is a prescription-only treatment option that is administered by injection to the affected areas every 4-to-6 weeks rather than being self-administered at home.

Home remedies for thinning hair

In addition to these medical interventions, there are also some home remedies and natural approaches that may be used. These remedies have limited data, but some people experiencing hair loss enjoy using them in conjunction with more proven treatments.


This home treatment is well known to just about everyone who has consulted Google to figure out what to do about their hair thinning. Unfortunately, those biotin gummies your favourite influencer is hawking aren't necessarily your best bet when it comes to treating hair loss. While supplementation can sometimes help if you have a particular deficiency, it's best to discuss your situation with your doctor and get blood work done to determine if you're low on key nutrients. Biotin, folic acid, vitamin D, zinc, and omega-3 and -6 fatty acids are all popular supplements for thinning hair.

It's worth noting that over supplementation with certain nutrients, such as selenium, vitamin A, or vitamin E, can actually contribute to hair loss. That's why your treatments, including home treatments, are best supervised by a professional.

Eat hair-healthy foods

Incorporating foods that are naturally rich in nutrients that support normal hair growth can be a good way to increase your intake of these nutrients without risking over-supplementation. Focusing on foods that contain proteins, healthy fats, and certain key vitamins and minerals can help you address nutritional gaps in your diet. Some ideas of foods to include in your diet are:

  • Walnuts, which contain healthy fats
  • Fatty fish such as sardines
  • Brazil nuts, which are rich in selenium
  • Eggs, which naturally contain protein and the B-vitamin biotin

Scalp treatments

While there isn’t reliable evidence for their efficacy, some people enjoy scalp treatments such as regular scalp massages or specialty shampoos. Claims that they can grow back hair are not supported, but these treatments won’t hurt and can provide a relaxing way to de-stress.

When should I see a doctor for my hair thinning?

You will likely be the first person to notice a difference in your hair density, so if you feel your hair is looking thinner or you're noticing more hair than usual coming out when you brush or shampoo, speaking to a healthcare professional can help you determine if there is cause for concern. It's possible that you're just experiencing a normal mature hairline, and that treatment is not necessarily required. But the best way to find out is to speak to a healthcare professional.

If you want to talk to a healthcare practitioner about hair loss options, start an online visit with Felix today.

Felix Team
Updated on:
February 19, 2023
Medically reviewed by
Dr. Sheila Wijayasinghe
Family Physician, MD, CCFP

The views expressed here are those of the author and, as with the rest of the content on Health Guide, are not a substitute for professional medical advice, diagnosis, or treatment. If you have any medical questions or concerns, please talk to your healthcare practitioner.

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