Hair loss is one of the most common problems both men and women of all ages experience and one that negatively affects their quality of life. Hair loss becomes even more apparent in times we experience heightened levels of stress, when our medication changes or, inevitably, as we age. But during seasonal transitions, many start to notice changes in the feel, look and quality of their hair and may be alarmed by the number of strands they see stuck in their brushes. This begs the question: Can the weather make you lose your hair?

Let's look at the science.

Every strand of hair falls out when it completes its development process. This period varies according to our genetics, and it takes approximately two to eight years for a single strand to complete its active growth phase.

The average human has 100,000 to 150,000 hair follicles on their scalp and about 5 million on their body. According to dermatologists, losing anywhere between 50 to 100 strands of hair every day is normal, so seeing a clump in the shower is no cause for alarm. However, if you are increasingly seeing more strands falling out and this shedding has continued uninterruptedly for two months or more, presenting itself as bald patches on the scalp or thinning of hair, it may be time to see a doctor.

What factors increase hair loss?

Hair growth is a very complex process that goes through three stages: anagen when it is actively growing, catagen when it stops growing and telogen when it starts to fall out. Our genetics and hormones determine the density and thickness of our hair. So, the prerequisite for healthy luscious hair is good genetics. However, various hormonal disorders, especially goiter and polycystic ovary syndrome (PCOS), can increase hair loss. Another important type of hair loss attributed to hormonal changes is reactive hair loss, which is seen in women after childbirth.

Physical factors such as medication or chemical treatments such as perms and bleaching and high heat from styling tools can also increase hair loss. If your diet is lacking in protein, vitamins, minerals, amino acids and essential fatty acids, all of which are necessary for hair growth, your hair may be looking dull or feel as if it is not growing at all. Following restrictive diets, undergoing surgery, experiencing infections and bearing daily stress, or lately pandemic stress, can all contribute to hair loss.

Link between nutrition and hair

The relationship between nutrition and hair loss continues throughout the year, not only during seasonal changes. Our hair absorbs nutrients from the foods we consume and builds itself up, while topical products and environmental factors can help support its health. Hair is the fastest growing tissue in our body after bone marrow, and hence, needs protein, vitamins and minerals to acclimatize to this rapid growth. In the absence of such nutrients, hair loss occurs, and existing hair loss may become more severe.

The most important nutrients our hair needs are iron, zinc, vitamin A, vitamin Bs (B2, B5, B6, B9, B12 and specifically biotin, B7), vitamins C and E, and essential fatty acids such as omega 3s and 6s. If you are lacking in any, your doctor can prescribe you supplements temporarily which may decrease hair loss.

Seasonal hair loss: a myth?

Though seasonal hair loss is still a debated topic, the general consensus is that weather changes can increase hair fallout, and it is more common in women. The reason is thought to be caused by hormonal changes or stress. At the same time, many doctors attribute it to environmental factors such as months of sea salt, pool chlorine and sun rays in the summer speeding up the wear and tear of strands.

Conversely, studies have shown that during summer, hair growth increases to protect the scalp from sunlight. Warmer weather also boosts the supply of nutrients needed to produce keratin, the protein hair is composed of, therefore increasing its production, which results in faster-growing, longer locks. That's why post-summer, after months of boosted growth, many people complain of excessive shedding, especially between September and November.

Scientists say the fact that seasonal hair loss is more common in women comes down to two main reasons: awareness, and hormonal and psychological changes. Women tend to be more aware of their hair's condition and spend more time on it daily. Women also go through more hormonal changes every month that impacts their psychological state, hence dermatologists assume that this effect also increases hair loss.

How to treat hair shedding

Your dermatologist needs to determine the cause of hair loss first, which most likely will be physiological. However, it can also be a symptom of an underlying disease or just your genetic makeup. Reactive hair loss, skin or hair diseases, autoimmune disorders such as alopecia (a condition that causes hair to fall out in patches on the scalp and body), infections, hormonal fluctuations and dominance of androgens, congenital diseases and tumors can all be to blame. For example, if genetics are to blame, you may be noticing male-pattern balding where you start losing hair from the top of your head or the front parts of your head.

After determining the cause, treatment should be planned accordingly. Minoxidil and Finasteride are Food and Drug Administration- (FDA) approved medical treatments for androgenic alopecia. However, they can cause various side effects. Platelet-Rich Plasma (PRP), mesotherapy, cellular treatments, stem cell and hair transplants in advanced cases are also among treatment options. If you are suffering from nutritional deficiencies, treatment will comprise of supplements, showing its effects in a couple of months. If it is due to hormonal disorders such as PCOS or goiter, you'll likely be referred to an endocrinologist to fix the root cause and it may take longer to see results.

What hair care products should I be using to combat hair loss?

Using sulfate-free shampoos with mild surfactants and choosing products without sodium lauryl sulfate and sodium laureth sulfate can be a good starting point, says dermatology specialist Dr. Hilal Gökalp. Serums or solutions that increase blood flow in the scalp via ingredients such as caffeine and those that contain various vitamins to combat dryness and dullness can also offer temporary fixes and support treatment. Especially after a summer of swimming, Gökalsp recommends her patients use moisturizing hair masks and conditioners from the midlength to the ends.

On that note, do anti-hair loss shampoos actually prevent hair loss?

These products can help shorten the shedding process in physiological hair loss. But if there is an accompanying disease or deficiency, it won't likely do much help, says Gökalp. The same goes for supplements. They can strengthen the hair and reduce shedding, but as with all health issues, the underlying problems must be addressed first.