Sometimes, a stray hair can be more than just a sign that your period is on its way. "If the hair is darker and coarser than your natural colour, it could mean you have a chronic hormone abnormality, which is most commonly polycistic ovary disease (PCOS)," said dermatologist Dr. David Lortscher, MD. This hormone disorder affects one in 15 women and is caused when ovaries are enlarged by cysts. If you notice your stray hairs popping up in conjunction with other PCOS symptoms like acne, a deepening of your voice, or irregular periods, call your doctor to treat it.
According to dermatologist Dr. Stephanie Daniel, MD, "If your hair is secondary to a hormone problem such as PCOS, it will be difficult to get rid of without addressing the underlying hormonal issue first."
If your stray hair gets friends — that is, if you start growing a patch of body hair out of nowhere — this could be a warning sign that something is not right. "A sudden new growth of hair in a specific area may mean that there is an underlying medical condition triggering new, aberrant hair growth," said dermatologist Dr. Linda Honet, MD. Though it's not common, this sudden hair growth in women could be a sign of a tumour in the adrenal gland or ovary.