Less common causes, especially in adults, are inadequate iron in the diet and an inability to absorb iron normally. Under a microscope, iron-deficient red blood cells are easy to spot, because they are smaller and paler than normal. However, symptoms are not as clear-cut. You may notice that your gums or the area around your nails is pale, and your nails may be brittle. Weakness and headaches may be clues.
Some people feel tired and short of breath.
Sometimes, stopping the bleeding and allowing iron supplies to build up naturally are all that is necessary. You may need to increase the amount of iron you get in your diet. Vitamin C helps your body absorb iron, so try having fresh citrus fruit with meals. And avoid tea, which hinders absorption. Before you take iron supplements, check with your doctor to see whether they are necessary and safe for you.