If you've ever suffered with hair loss, you'll know it's a complicated experience. It can shatter your self confidence and have you spending many late night hours on Google looking for a reason why.

Unfortunately, the reasons why someone might experience hair loss can vary immensely. And without a full suite of tests, sometimes it can be difficult to pin point just one cause - especially when stress is involved.

We spoke with dermatologist Dr. Neera Nathan, a Harvard-trained specialist, and asked her all our nitty-gritty hair loss questions. What are the most common causes? How much loss in normal? Is there any way to prevent it? Dr Nathan says there's no one answer. She favours an everything and the kitchen sink approach and advises to wash your hair regularly with anti-dandruff shampoo.

We know that it's quite common for men to experience hair loss, but is this something that is common in women?

Hair loss is incredibly common for women, but for whatever reason it is a more taboo topic. The truth is most women will experience hair loss at some point in their lifetime.

What are some of the most common causes of hair loss in women?

There are many different causes. Stress - both physical stress, like childbirth, and emotional stress, like loss of a loved one - can cause hair loss. Hormone changes and inflammation can also trigger hair loss in women. Then there are conditions like alopecia and PCOS.

Is there a particular vitamin deficiency that can cause hair loss?

Vitamin D and iron deficiency both can cause hair loss. I always recommend vitamin D level testing and ferritin levels (which measure iron stores) especially for anyone experiencing diffuse hair shedding because correcting these levels can support healthy hair growth.

For women suffering with hormonal hair loss, like postpartum women, women with PCOS or those using the Pill, is this more complex than other types of hair loss?

Postpartum hair loss is actually a bit different. It is classified under telogen effluvium, which is a self-limited form of stress induced hair loss and usually resolves on its own by your baby’s first birthday.

Androgenetic alopecia is the most common form of hormonal hair loss, but it is not always caused by an imbalance of hormones in your blood. Instead, it is caused by an excess of DHT, a form of testerone, within the hair follicle that causes hair loss. This is a lifelong form of hair loss, but can be improved with treatments.

How much hair loss is to be considered normal? When would you start considering it abnormal?

It is normal to lose between 100 and 150 hairs per day. If you are losing more than 200 hairs per day - and there are visual scales online that can help you figure out this number - it is likely abnormal hair shedding.

How can you stop hair loss? What is the process here?

The good news is it is possible to slow and even reverse hair loss. Starting treatment as soon as you notice hair loss is important for the best results. First, I recommend washing your hair more often if you experience hair loss. At least a few times per week for straight or wavy hair, and once per week for curly or textured hair.

I recommend using an anti dandruff shampoo (even if you don’t have dandruff) like Nizoral or Head & Shoulders as these have been shown to decrease hair fall. Alternatively, you can use a shampoo with hair growth actives like the Vegamour Gro Revitalizing Shampoo. I recommend starting a hair growth topical. There are multiple you can try here - Rogaine (minoxidil) is the gold standard, but if you want a natural option, I recently co-developed the Vegamour GRO+ Advanced Serum which was shown in a clinical study to significantly reduce shedding and increase hair density. I recommend combining this serum with a dermaroller to help increase serum absorption. If you have sudden or severe hair loss, I recommend seeking care from a board certified dermatologist for diagnosis and treatment.

Is there any way to prevent hair loss before it starts?

Taking care of your personal health, eating well, sleeping, avoiding tight hair styles, avoiding chemical treatments or excess heat styling may help prevent hair loss in some cases.

Are there any tests or blood work that you recommend those with hair loss should look into?

As mentioned above, vitamin D and ferritin. I also generally recommend having thyroid levels checked as low thyroid can be linked to hair loss.

What are the best ways to regrow hair once its been lost?

Antidandruff/hair growth shampoos and topicals, low level laser therapy (LLLT) combs & helmets, dermarollers, oral medications like minoxidil, spironolactone and finasteride, in office platelet rich plasma injections may all be helpful.

A combination or “kitchen sink” approach to hair loss is generally more effective than any single treatment.

Do you have any advice or words for those trying to manage hair loss?

Hair loss can be emotionally devastating. Just know you are not alone and there are things you can do to improve it.