By 2. Period
Your period can cause anemia if you lose a large amount of blood each month. This is one of the most common reasons for iron deficiency in people who menstruate. When you lose blood, you also lose iron. Your body needs iron to make hemoglobin, the protein in red blood cells that carries oxygen.
Heavy periods may last longer than seven days or require very frequent pad or tampon changes. You might pass large clots or need double protection to prevent leaks. Over time, steady blood loss can lower your iron stores. Common signs include feeling tired or weak, pale skin, shortness of breath with mild activity, and dizziness or headaches.
Certain conditions can cause heavier bleeding, such as hormone imbalances, uterine fibroids, bleeding disorders, or problems after childbirth. Doctors may treat heavy menstrual bleeding with hormonal therapy or medicines that reduce blood loss, and iron supplements may help rebuild iron levels. Medical evaluation should take place if heavy bleeding or anemia symptoms continue in order to identify the cause and prevent further iron loss.
3. Surgeries
Surgery can lead to anemia when you lose blood during or after a procedure. Even with careful planning, major operations often involve some blood loss. If a large amount of blood is lost, your body may not have enough red blood cells to carry oxygen effectively to tissues and organs.
You may notice fatigue, shortness of breath, or pale skin within days after surgery. Blood counts are usually checked before and after the procedure to monitor for changes. Surgeries with higher blood loss risk include heart surgery, joint replacement, major abdominal operations, and procedures on the stomach or intestines.
Some digestive tract surgeries can also reduce iron or vitamin absorption, which may lead to iron deficiency anemia over time. After surgery, your care team may recommend iron supplements, fluids, or a blood transfusion based on blood loss and overall health. Pre-surgical testing and correction of low iron levels should be considered to reduce postoperative anemia risk.
4. Excessive Bleeding
When you lose blood, you also lose red blood cells. If your body cannot replace them quickly enough, you can develop anemia. Blood loss remains one of the most common causes. Without enough red blood cells, less oxygen reaches your tissues, which can affect your energy and overall function.
Heavy menstrual periods often lead to this problem. If your period lasts more than seven days, soaks through pads or tampons quickly, or includes large clots, you may lose a significant amount of blood each month. Bleeding disorders, stomach or intestinal ulcers, colon growths or cancer, and injury or surgery can also cause excessive blood loss.
Internal bleeding from ulcers, colon polyps, colon cancer, or long-term use of nonsteroidal anti-inflammatory drugs may occur without visible signs. Sudden blood loss after trauma or surgery can cause rapid symptoms such as weakness, dizziness, shortness of breath, or fatigue.
5. Blood Disorders
Blood disorders can lower your red blood cell count or change how these cells function. When this happens, your blood cannot carry enough oxygen to your tissues. You may feel tired, weak, dizzy, or short of breath because your organs are not getting the oxygen they need.
Some blood disorders are inherited, so you are born with them, while others develop later due to bone marrow problems. Conditions that can cause anemia include sickle cell disease, thalassemia, aplastic anemia, hemolytic anemia, and bone marrow cancers such as leukemia or multiple myeloma. Each condition affects red blood cells in a different way.
In sickle cell disease, red blood cells have an abnormal shape and break down faster than normal. Thalassemia affects hemoglobin production. Hemolytic anemia causes early destruction of red blood cells due to immune disorders, infections, or certain medicines. Aplastic anemia and bone marrow cancers reduce blood cell production.
6. Lack of Iron
Your body needs iron to make hemoglobin, the protein in red blood cells that carries oxygen. When you do not have enough iron, your body produces fewer healthy red blood cells. This leads to iron-deficiency anemia, which is the most common type of anemia worldwide.
Blood loss is a frequent cause of low iron. Heavy menstrual periods, stomach or intestinal bleeding, ulcers, colon conditions, or long-term use of nonsteroidal anti-inflammatory drugs can reduce iron levels. Digestive diseases such as celiac disease or Crohn’s disease, as well as stomach or weight-loss surgery, can limit how much iron your body absorbs.
Diet also plays a major role. Iron-rich foods include lean red meat, beans and lentils, eggs, dark green leafy vegetables, and iron-fortified cereals and breads. Vitamin C from foods such as oranges, strawberries, and tomatoes improves absorption. Without enough iron, you may feel tired, weak, dizzy, short of breath, or notice pale skin and cold hands and feet.
7. The Wrong Diet
Your body needs iron, vitamin B12, and folate to produce healthy red blood cells. If your diet lacks these nutrients, you increase your risk of anemia. Without enough of them, your bone marrow cannot make red blood cells that carry oxygen efficiently.
You may not get enough iron if you eat very little meat, poultry, seafood, beans, or leafy green vegetables. Diets that restrict multiple food groups can lower iron intake. Low fruit and vegetable intake can worsen the problem because vitamin C helps your body absorb iron.
Vitamin B12 comes mainly from animal foods such as meat, dairy, and eggs, so a poorly planned plant-based diet may lead to deficiency. Folate from fortified grains, beans, and leafy greens also supports cell production. Long-term nutrient gaps can reduce red blood cell formation and lead to anemia symptoms such as fatigue and weakness.
8. Excessive Exercise
You can develop anemia if you train hard without giving your body enough recovery time or proper fuel. Long and intense workouts increase your need for iron and other nutrients. If you do not replace them, your red blood cell levels can fall and limit oxygen delivery to your muscles.
Heavy endurance training, such as long-distance running, can cause small but repeated blood loss. You may lose iron through sweat, minor digestive bleeding, or foot impact that damages red blood cells. Intense exercise also increases iron use, may reduce absorption during heavy training, and can combine with low calorie or nutrient intake.
If you follow a strict diet while training, your risk increases further. Low iron, vitamin B12, or folate intake can slow red blood cell production. Common signs include ongoing fatigue, shortness of breath during normal workouts, pale skin, and slower recovery. Blood tests can confirm low iron levels and reduced red blood cell counts.
9. Eating Disorders
Eating disorders can lead to anemia when you do not get enough nutrients from food. Your body needs iron, vitamin B12, folate, and protein to produce healthy red blood cells. When you restrict food, binge and purge, or follow extreme dieting patterns, your intake of these nutrients drops.
Conditions linked to anemia include anorexia nervosa, bulimia nervosa, and binge eating disorder with strict dieting cycles. If you eat very small amounts of food, your iron stores can fall. Frequent vomiting can irritate your stomach and cause small amounts of blood loss. Poor nutrition can also lower vitamin B12 and folate levels, which may lead to other forms of anemia. You may notice tiredness, pale skin, shortness of breath, dizziness, or cold hands and feet. These symptoms can develop slowly. Eating disorders affect both teens and adults.
10. Autoimmune Disorders
Autoimmune disorders can cause anemia when your immune system attacks your own healthy cells. Instead of protecting you, it targets parts of your body by mistake. This damage can lower your red blood cell count and reduce the amount of oxygen your blood carries.
In some cases, your immune system destroys red blood cells faster than your body can replace them. This condition is called autoimmune hemolytic anemia. When red blood cells break down too quickly, you may feel tired, weak, dizzy, or short of breath because oxygen delivery drops.
Other autoimmune diseases such as rheumatoid arthritis, lupus, Crohn disease, and ulcerative colitis can cause long-term inflammation that interferes with iron use and slows red blood cell production. Some stomach-related autoimmune disorders reduce vitamin B12 absorption. Without enough vitamin B12, your body cannot produce healthy red blood cells, which can lead to anemia.
