My mum stuffed a sanitary towel into my hand as I jumped out of the car on the way to school. “Knowing our family, you might not need it for a while, but it’s always good to be prepared,” she said, winking as I closed the door.

I was 15 when I had my first period, just like my mother, my aunties and my grandma. Although the red arrival was meant to mark a watershed moment of diary-marking and tins stuffed with pads, my 28-day count soon fell by the wayside, as my periods became nothing more than an annual event. I shrugged. Noticing the cramps and moans of my peers, my absent period appeared to be a blessing of genetics.

In my final year at the University of Leeds I went to the doctor about my acne and thought I might as well ask about my lack of periods. “We’re going to get you tested for polycystic ovary syndrome, commonly known as PCOS,” my doctor explained.

“What does that mean?” I asked.

“PCOS is very common. It could be the explanation for your acne and your periods,” my doctor told me. “They’re common signs and some women notice excess hair and weight gain. The cysts on the ovaries can affect fertility – but don’t panic just yet.”

I tried to decipher the medical jargon with an NHS pamphlet that explained the condition. Although seven in 100 women in the UK have PCOS, up to 70% of people who have it are undiagnosed. The condition has several variants, but it commonly involves testosterone and cysts.

The over-production of insulin in a sufferer’s body can lead to an increased level of testosterone. This can result in excessive body hair, a risk of type 2 diabetes, and increased levels of cholesterol later in life. Cysts tend to appear on the eggs of women with the condition, meaning that there is a greater risk of infertility for the women who have it.

Periods and skin complaints were irritating yet expected worries at 21, but the mention of infertility sent me into a panic. The idea of childbearing was one I had always taken for granted. Although I had always challenged my parents to correct “when” to “if” when they spoke about my having a family, the possibility, however distant, was important to me. Was I meant to tell my new partner that I might struggle to conceive? It seemed a big challenge when I was just about nailing the art of paying my rent on time.

Jenny Brown (not her real name), an English student at the University of Leeds, also discovered that she had the condition while at university. “I stopped taking the pill in first year as I wasn’t having regular sex,” she says. “My period didn’t turn up after six months so I went to the doctor who gave me a blood test. A month later I received a letter saying I’d been booked in for a hospital appointment.

“This was a shock. I went to the appointment, which was uncomfortable, as he inserted a camera up my vagina. The doctor pointed out lumps on my ovaries which he said were cysts. This was confirmed weeks later, but there was a distressing time in between where I didn’t understand the diagnosis or what it meant.”

Although the majority of PCOS symptoms are treatable, a lack of awareness surrounding the illness means that plenty of women who are diagnosed are still unaware of the implications. Anna Trotter, a Spanish and history of art student at the University of Leeds, says: “When I was diagnosed with PCOS, I panicked because I’d never heard of it, so I got upset and worried it was something more serious. I was put on the pill to regulate it and have been on it since. Apart from that I haven’t been back to the doctor and I’m not sure if I’m supposed to do anything about it.

“Occasionally I panic that it could affect my fertility but then I tell myself that it might not. Also there are other treatments with regards to fertility, so hopefully it won’t be a massive problem.”

Jan Tilley, a final-year English student at the University of Leeds, struggled with excessive hair and acne due to the condition, and found that the visible signs disrupted her day-to-day life: “I felt insecure when I first found out, and it affected my confidence. It took some time, but I came to the conclusion that the majority of it was in my head. Nobody could tell or even cared what I looked like. It’s good to know that you can exercise a certain amount of control over PCOS through lifestyle.”

For me, as I graduate this summer, I will do so with more uncertainties than the average twenty-something. At first, that thought terrified me. But it is good to know that I am not the only one with the condition and that I am not alone.

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• This article was amended on 13 May 2015 to anonymise one of the interviewees.