AFP via Getty Images In a picture taken on November 21, 2012, Drishti Silwal (back row L), a 12 year old Brahmin Nepali girl reads a book at school in Kathmandu. Dristhi returned to school after spending 7 days staying in the darkness of her bedroom as part of an isolation ritual during her first menstruation. Usually Brahmans stay isolated for 21 days in the dark, without the permission to look outside, see any men, pray or cook, but in modern families the ritual can be reduced to 7 days and Drishti was allowed to read. AFP PHOTO / MATTHIEU ALEXANDRE (Photo credit should read MATTHIEU ALEXANDRE/AFP/Getty Images)

Menstruation is the number one reason why girls in developing countries miss school, or drop out altogether, and there are a number of reasons that contribute to this.

A girl's transition into womanhood is often marked by the beginning of her menstrual cycle, an occasion that is celebrated in many cultures as an important rite of passage. But in many parts of East Africa, it marks the beginning of a lifetime of discomfort, embarrassing health problems, and even harassment. It marks the beginning of schoolyard bullying, missed days of school, and the start of a lifetime viewed as a sexual object.

But it might surprise you to learn that one of the most difficult parts about being a woman is also one of the most natural: menstruation. Despite the fact that it directly affects women everywhere, menstruation is rarely talked about. That is part of the problem, and it is especially obvious in developing countries.

It won't surprise you to hear that women are among the world's most vulnerable populations. It probably won't surprise you to hear that women face more challenges than men, as they are often primary caregivers to their families while trying to survive in a patriarchal system.

First, there is the issue of poverty. The cheapest package of sanitary pads in Kenya costs 55 KSH -- approximately $0.75 CAD. For a country where the average daily wage is just about double that, it isn't hard to understand why purchasing sanitary pads is a luxury for most women. As a result, girls will resort to using alternative methods of menstrual management, such as rags, leaves, newspaper, bits of mattress stuffing, even mud. As you can imagine, these methods are not comfortable, nor are they effective, and they can lead to very serious health concerns. They definitely don't help girls feel clean or confident.

But the problem runs deeper than extreme poverty. In many parts of the world, the customs and traditions surrounding menstruation are oppressive and destructive, and can severely limit a woman's daily life. For example, in rural Masai regions of Kenya, girls are forbidden from touching livestock, preparing food or consuming animal products for fear of contamination. In communities in India menstruating girls must not drink from the same water source as her village. In remote areas of Nepal, the practice of chhaupadhi banishes women into isolated huts for the duration of her period and forbids her from interacting with her community.

These traditions are born out of a lack of understanding. Menstruation is not a dirty word. It is not a disease, a condition, or something to be afraid of. And it certainly should not be such a destructive part of a woman's life.

Providing menstrual health education works towards breaking down these destructive practices. It is no secret that an empowered woman is the most effective catalyst for sustainable change, and addressing the menstrual taboo is the first step.

Girls in Kenya will miss an average of 4.9 days of school each month due to her period -- adding up to 20 per cent of the school year. This puts female students at a distinct disadvantage as they enter secondary school and severely decreases her odds of continuing on to post-secondary school. If schools had the resources and commitment to teaching menstrual health education to their students, girl's attendance would improve, academic performance would improve, and their overall self-confidence would improve.

Initiatives like Femme International's Feminine Health Management Program has developed an innovative and effective program that not only provides essential health education to schoolgirls, but also provides them with sustainable forms of menstrual management. This combination of education and distribution tackles the problem of deliberate absenteeism from the ground up, and provides young girls with the tools they need to stay safe, healthy and confident -- every day of the month!

Menstruation is a natural part of every woman's life, and it should never be seen as a source of embarrassment. It certainly should not isolate, oppress or shame women. Providing menstrual health education to young women empowers them to achieve their potential, and take advantage of as many academic and professional opportunities as possible.