Is stress literally making your hair fall out? Well, there could be more your hair is trying to tell you. To tell if you’re stressed, look not to your face for wrinkles but into your tresses. A new study reveals that a single strand of hair can divulge just how stressed you are.

A study published in the Journal of Clinical Endocrinology & Metabolism found that your hair can show trends of the stress hormone cortisol over a period of several months. By comparison, blood tests can only reveal stress levels at a single point in time, but hair stands as a better tool for evaluating not only stress levels but risk of cardiovascular disease. Having high levels of cortisol for long periods of time can put you at a higher risk of coronary heart disease, peripheral artery disease, stroke and diabetes.

Your hair can tell you quite a bit about your health without a microscope, from the texture to how much of it falls out. Some conditions, like dandruff, are more noticeable than others. While it’s not harmful, dandruff can be linked with risk factors like stress, obesity, eczema and psoriasis. A condition called telogen effluvium in which hair falls out in handfuls is brought on by a shock to your system, like severe stress, thyroid problems and crash diets. Hair typically grows back right away.

Hair color can even hint at potential health risks. Blondes should be careful to keep covered in sunlight. Fair-haired women are also more prone to developing age-related macular degeneration, an eye condition that can cause blindness. Brunettes are more likely to suffer hair loss because they have less of it to begin with; brown strands are coarser than lighter ones. And redheads happen to have a 90 percent greater risk of developing Parkinson’s because of the same gene mutation that causes their fiery hue.

There’s more to hair than flair.