Anemia refers to the lack of red blood cells and heme in the blood. Anemia is divided into several different situations, one of which is iron deficiency anemia. The so-called iron deficiency anemia is that the iron content in red blood cells is too small, which is also the most common one of all anemia situations. Oxygen in the blood carries heme to all parts of the body, and iron is a very important component in heme. Usually, we can get the iron we need from food. Usually, people with iron deficiency anemia have insufficient iron intake in their diet, problems in the body's ability to absorb iron or blood loss. Women are more likely to suffer from iron deficiency anemia, because women will lose blood regularly every month during their physiological period. On average, about 20% of women and 50% of pregnant women have iron deficiency anemia. Only about 3% of men will have iron deficiency anemia. When the iron stored in the body and bone marrow is exhausted, iron-deficiency anemia will gradually form, and the function of women in making blood and iron is not as good as that of men, and because the menstrual blood loss is greater than that of men, most of them suffer from iron-deficiency anemia before menopause. If men and postmenopausal women suffer from iron deficiency anemia, most of them are due to long-term gastrointestinal ulcer bleeding, taking too much aspirin, anti-inflammatory drugs or cancer patients. If the situation of iron deficiency anemia is not serious, there are usually few symptoms. However, if the iron content in heme is below a certain level, the patient may have symptoms such as pallor, fatigue, irritability, weakness, shortness of breath, hypotension, dizziness, oral pain, cracked nails, headache and sudden preference for a particular food or loss of appetite when posture changes due to hypotension. The high risk groups of iron deficiency anemia include: premenopausal women, because she will lose blood every month; Pregnant or breastfeeding women, because they need more iron; Babies, children, young teenagers who grow rapidly in adolescence, and people who usually have insufficient intake of iron, meat and eggs. To prevent iron deficiency anemia, we should first pay attention to diet, and take a balanced intake of iron-rich foods such as red meat, liver, egg yolk and grains. If the iron intake in the diet is insufficient or iron deficiency is serious, you must supplement iron. Vitamin C can help the absorption of iron and the production of heme, so the intake of vitamin C should be sufficient. It should be noted that milk and some drugs that neutralize stomach acid will hinder the absorption of iron, so try not to eat it with iron-containing foods. Doctors usually prescribe iron for patients with severe iron deficiency anemia, and the situation will improve after taking it for about two months.