Iron is vital to your overall health — it plays a role in everything from the way your brain develops to how healthy and strong your nails and hair grow — and a severe lack of iron can make you feel downright lousy as well as lead to some serious health consequences.

An estimated 3.5 million Americans suffer from anemia, with women having a higher risk because they lose so much blood during their periods, New York-based dietitian Lisa Hayim says. “If your iron deficiency becomes severe, it can lead to heart problems or arrhythmia, and it can be extremely detrimental during pregnancy,” she says. While a mild iron deficiency during pregnancy probably won’t lead to any long-lasting consequences, severe anemia can lead to low birth weight and developmental delays.

Below, Hayim shares six potential signs of iron deficiency to look out for. If they sound familiar, increase your intake of iron-rich foods such as lean beef, salmon, egg yolks, leafy green vegetables, iron-fortified cereals, beans, and tofu. There’s some evidence that shows iron absorption is increased when combined with foods that contain vitamin C, so Hayim recommends pairing them together when you can (for example, you could try adding some lemon juice to a bean-based hummus or dip).

1. Pale skin: A sickly, paler-than-usual skin tone is to be expected when you have a cold or the flu, but it’s also a possible sign that you’re not getting enough iron. Another possible tip-off? Check the inside of your mouth — if your gums or the inside of your lips seem less red than usual or your tongue looks swollen, you may want to stock up on steak and spinach.

2. Heavy periods: A 2014 Finnish study found that 27 percent of women with heavy periods were also anemic and 60 percent were iron deficient. While many women take their periods as a given, if you find yourself constantly bleeding through tampons or pads in an hour or less and you find yourself feeling sluggish or fatigued, it’s possible you could benefit from taking an iron supplement.

3.Lethargy or fatigue: Iron is a key component of your red blood cells, which are responsible for circulating oxygen throughout your body to your muscles, Hayim says. Because of this, an iron deficiency can decrease your capacity for oxygen-carrying, which means you may notice that you’re suddenly having a harder time pushing through your normal workout or feeling beat when doing something as simple as walking up the stairs.

4. Headaches: This is one of the most common signs of iron deficiency and goes back to your oxygen-carrying capacity: when you have low iron levels, your body can’t circulate as much oxygen to your brain, which is what causes your headaches.

5. Hair loss: It’s normal to lose about 100 hairs per day, but if your hair is suddenly shedding in large clumps, it could be because a lack of oxygen in your red blood cells has pushed your hair into its “resting” phase faster than it ordinarily would. Luckily, this is temporary and will reverse itself once you get your iron levels worked out — however, hair grows slowly, so you might have to wait three to six months before your hair goes back to normal.

6. A sudden craving for ice: Unusual, yes, but it’s also a telltale sign of anemia. This condition is called pica, and Hayim says that it’s defined by an inexplicable craving for non-nutritive sources such as ice, dirt, and in some extreme cases, paint or metal.

Do the above symptoms sound like you? Talk to your doctor, who can do a ferritin test and determine whether you need to take an iron supplement. Hopefully, you’ll be feeling like yourself again in no time.

Alanna is a freelance writer and editor living in Brooklyn. She's written for Shape, Fitness, Cosmopolitan, Reader's Digest, Vivala.com, and more, and mostly spends her time now searching for the perfect coffee shop, writing about all things health and wellness, taking photos of her dog, and trying (and failing) to become a dedicated runner. Follow her on Twitter or Instagram.