The most common symptoms of anemia are tiredness, weakness, and shortness of breath during activity. Other anemia symptoms include dizziness, headaches, and cold hands and feet.
About 9.3% of people aged 2 and older in the US had anemia between 2021 and 2023. Anemia is a sign of an underlying condition, such as low iron levels, low vitamin B12 levels, blood loss, or a long-term illness.
A blood test can show what’s behind your anemia. You can get a lab requisition online for it without waiting for a primary care provider.
What is anemia?
Anemia means your blood has fewer healthy red blood cells, or less hemoglobin, than it should.
Hemoglobin is an iron-rich protein in red blood cells that carries oxygen from your lungs to the rest of your body. When you have anemia, your body doesn’t get enough oxygen-rich blood.
Red blood cells are made in your bone marrow, the spongy tissue inside your bones. To make them, your body needs iron, vitamin B12, and folate.
Hemoglobin levels that may indicate anemia
A hemoglobin level below the cutoff for your age, sex, or stage of pregnancy may indicate anemia. The lower the level, the more severe the anemia.
| Group | Anemia if below | Mild (g/dL) | Moderate (g/dL) | Severe (g/dL) |
|---|---|---|---|---|
| Men | 13.0 | 11.0 to 12.9 | 8.0 to 10.9 | Below 8.0 |
| Non-pregnant women | 12.0 | 11.0 to 11.9 | 8.0 to 10.9 | Below 8.0 |
| Pregnancy, first and third trimesters | 11.0 g/dL (110 g/L) | 10.0 to 10.9 | 7.0 to 9.9 | Below 7.0 |
| Pregnancy, second trimester | 10.5 g/dL (105 g/L) | 9.5 to 10.4 | 7.0 to 9.4 | Below 7.0 |
Common anemia symptoms
Anemia symptoms can start quickly or develop gradually, depending on the cause. How strongly they feel depends on how low your hemoglobin is and how fast it has dropped. If your anemia is mild, you may not have any symptoms.
Early symptoms of anemia
The first symptoms of anemia may include feeling tired more often than usual, or during exercise. You might need extra rest after a workout, or get winded on the stairs. Other common symptoms include:
- Pale skin
- Shortness of breath
- Dizziness or lightheadedness
- Headaches
- Cold hands and feet
You may also have trouble concentrating, feel irritable, or lose your appetite. Some people notice a pounding or whooshing sound in their ears.
Symptoms of severe anemia
As anemia worsens, your heart and lungs may work harder to deliver oxygen throughout your body. Signs of severe anemia include:
- Very pale skin, or paleness inside your lower eyelids or mouth
- Fast breathing or a fast heart rate
- Dizziness when you stand up
- Fainting
- Chest pain, particularly if you have heart disease
Get emergency medical care if you have chest pain, shortness of breath while resting, fainting, new confusion, an irregular heartbeat, or bleeding that won’t stop. Black, tarry stools or vomiting blood can also be signs of internal bleeding and need urgent care.
What causes anemia, and what are the main types?
Anemia happens when your body loses red blood cells, doesn’t make enough, or destroys them too quickly. Iron, vitamin B12, and folate deficiencies can prevent your body from making enough healthy red blood cells. Iron deficiency is the most common cause, responsible for about 66% of anemia cases worldwide. Sometimes, chronic conditions, inherited blood disorders, sudden blood loss, or problems with the bone marrow can also cause anemia.
Iron-deficiency anemia
Iron-deficiency anemia happens when your body doesn’t have enough iron to make hemoglobin. The most common causes are:
- Blood loss: heavy periods, or slow bleeding in the stomach or bowel from ulcers, polyps, colon cancer, or regular use of aspirin or other NSAIDs
- Poor iron absorption: celiac disease, inflammatory bowel disease, or stomach surgery, including gastric bypass
- Needing more iron: pregnancy and periods of fast growth
You’re more likely to develop iron-deficiency anemia if you have heavy periods, are pregnant or recently gave birth, follow a vegetarian or vegan diet, or donate blood often. Infants and children going through growth spurts are also at higher risk. If you’re pregnant, read more about iron deficiency in pregnancy.
You can also have low iron before you develop anemia, so low iron symptoms can start while your hemoglobin is still normal. Along with the usual symptoms of anemia, low iron can cause cravings for ice or other things that aren’t food (pica), restless legs, and brittle or spoon-shaped nails.
Vitamin B12 deficiency anemia
A lack of vitamin B12 means your body can’t make enough healthy red blood cells, and the ones it does make are larger than normal. You may feel tired or weak, and you might have pale skin, a pounding heartbeat, a poor appetite, or a sore mouth or tongue.
Low B12 can also damage your nerves. Your hands and feet might become numb or tingly, and you might have balance problems, confusion, or poor memory.
One cause is pernicious anemia, an autoimmune condition in which your immune system attacks the lining of your stomach by mistake. As a result, your body can’t make intrinsic factor, the protein it needs to absorb vitamin B12. Many older adults run low on B12 because they don’t have enough stomach acid to absorb it from food.
Folate deficiency anemia
Folate, also called vitamin B9, is another nutrient your body needs to make red blood cells. Without enough of it, your red blood cells become large, causing megaloblastic anemia. Low folate can cause open sores on your tongue and inside your mouth, as well as changes in the color of your skin. Common causes of low folate include:
- Not eating enough folate-rich foods, such as leafy greens, beans, and fortified grains
- Drinking heavily over a long period
- Celiac disease or inflammatory bowel disease, which can reduce how much folate you absorb
Anemia of inflammation
Anemia of inflammation, also called anemia of chronic disease, affects people with conditions that cause inflammation. These include infections, rheumatoid arthritis, lupus, cancer, chronic kidney disease, inflammatory bowel disease, diabetes, and heart failure. It is the second most common type of anemia, after iron-deficiency anemia.
During inflammation, your liver makes more of a hormone called hepcidin, which reduces how much iron you absorb from food and traps the iron your body has stored. As a result, your bone marrow runs short of iron even when your body has plenty, so it makes less hemoglobin.
Inflammation can also reduce the amount of erythropoietin (EPO) your kidneys produce. EPO is the hormone that signals your bone marrow to make red blood cells. Your bone marrow may not respond normally to EPO, and your red blood cells may die sooner than usual. Anemia of inflammation is usually mild or moderate, with symptoms similar to those of other types of anemia.
Other types of anemia
Some types of anemia run in families, and a family history of an inherited anemia may raise your risk. Others come from sudden bleeding, red blood cells breaking down too fast, or a problem in the bone marrow.
- Sickle cell disease and thalassemia: These inherited conditions change how your body makes hemoglobin, so red blood cells form poorly or break down early.
- Anemia from sudden blood loss: Heavy bleeding from an injury, surgery, or the digestive tract removes red blood cells faster than your body can replace them.
- Hemolytic anemia: Red blood cells are destroyed faster than they can be replaced. Causes include autoimmune conditions, infections, certain medications, and inherited blood disorders.
- Aplastic anemia: This is a rare but serious condition in which your bone marrow can’t make enough new blood cells.
Is anemia dangerous?
Anemia can be dangerous, but it usually improves once the underlying condition is treated. It is more likely to be dangerous in four situations:
- It’s severe. Severe anemia means a hemoglobin level below 8.0 g/dL for adults, or below 7.0 g/dL during pregnancy. The lower your hemoglobin goes, the less oxygen your organs get, so your heart beats faster to make up for it. Over time, this strain can thicken the heart muscle, cause an irregular heartbeat, and lead to heart failure.
- It happens fast. Symptoms of anemia are worse when hemoglobin falls quickly, such as after sudden blood loss, because your body has no time to adjust.
- You have heart disease. Anemia can make your heart beat faster while the heart muscle itself gets less oxygen. In people with narrowed heart arteries, this can bring on chest pain. It also makes heart failure more dangerous. People with heart failure who also have anemia have about twice the odds of dying as people with heart failure who don’t.
- You are pregnant. Serious or untreated anemia in pregnancy raises the risk of preterm birth, low birth weight, and heavy bleeding during delivery.
Anemia can also be a sign of a more serious condition, such as bleeding in your stomach, kidney disease, cancer, or an autoimmune disease. So even mild symptoms are worth a blood test.
How is anemia diagnosed?
Your doctor diagnoses anemia using your medical history, a physical exam, and test results. They may ask what you eat and if anyone in your family has had anemia. During the exam, they look for signs of anemia, such as a pale tongue or brittle nails. A complete blood count (CBC) is a blood test that shows anemia.
What a complete blood count shows
The CBC measures your red blood cell count, hemoglobin, hematocrit, and mean corpuscular volume (MCV). Hematocrit is how much space red blood cells take up in your blood. MCV is the average size of your red blood cells.
Tests that find the type of anemia
Doctors use the MCV, the average size of your red blood cells, to sort anemia into three groups. Knowing the group tells your doctor which follow-up tests to order.
| Red blood cell size (MCV) | Common causes |
|---|---|
| Small (under 80 fL) | Iron deficiency, thalassemia, and sometimes anemia of inflammation |
| Normal (80 to 100 fL) | Kidney disease, anemia of inflammation, and aplastic anemia |
| Large (over 100 fL) | Low vitamin B12 or folate, heavy alcohol use, and an underactive thyroid |
Follow-up tests can include ferritin and other iron tests (serum iron, transferrin saturation, and TIBC), vitamin B12 and folate levels, and a reticulocyte count. Ferritin indicates how much iron your body stores. A reticulocyte count shows how quickly your bone marrow is making and releasing new red blood cells. If kidney disease is possible, urine tests check how well your kidneys are working.
How to get tested for anemia without a primary care provider
If you have noticed signs of anemia, you can get tested without a primary care provider. Through Your Doctors Online, a licensed doctor can issue a lab requisition for CBC, iron, vitamin B12, and folate tests. You then give a blood sample at a lab near you. Once your results are in, the doctor reviews them with you and can prescribe treatment or recommend that you be seen in person.
How is anemia treated?
Treatment depends on the cause of anemia and its severity. The goal is to treat the cause and raise your red blood cell count, so your body gets the oxygen-rich blood it needs.
For iron-deficiency anemia, iron supplements are the most common treatment. You take them until your hemoglobin and iron stores are back in the normal range, which often takes three to six months. Common iron tablets include ferrous sulfate, ferrous gluconate, and ferrous fumarate. Most people feel better within about a week of starting iron.
Iron is absorbed best on an empty stomach with a source of vitamin C. If it upsets your stomach, take it with a small amount of food. Keep it apart from antacids, tea, and coffee. A stool softener can help if iron makes you constipated. Eating iron-rich foods also helps keep your levels up.
Too much iron can damage your organs, so check with a doctor before you start taking it. You can get an online consultation for the treatment of iron-deficiency anemia.
IV iron, given through a vein, is used when tablets aren’t tolerated, can’t be absorbed, or can’t keep up with ongoing blood loss. For more on dosing and timing, see how to increase hemoglobin.
For low vitamin B12, your doctor can prescribe B12 to take by mouth, as a nose spray, or as a shot. Folate deficiency is treated with folic acid tablets, usually 1 to 5 mg daily for adults. Don’t start high-dose folic acid on your own before a B12 test because large doses can correct the anemia caused by low B12 but not the nerve damage.
A blood transfusion can quickly increase the number of red blood cells in your blood when anemia is serious. Doctors decide on a transfusion based on your hemoglobin level, your symptoms, and other health conditions, such as heart disease.
Frequently asked questions
Anemia can develop quickly after sudden blood loss, such as from an injury, surgery, or bleeding in the stomach or bowel. It can also happen when red blood cells are destroyed faster than your body can replace them, as with hemolytic anemia.
No, anemia does not usually mean you have cancer, although some cancers can cause anemia. Cancer can cause anemia by affecting the bone marrow or by causing slow bleeding in the stomach or bowel.
If a man or a woman who no longer gets periods has iron-deficiency anemia with no obvious cause, the digestive tract may need to be checked for bleeding. This can include an endoscopy or colonoscopy, which uses a camera to examine the upper and lower digestive tract.
If you have anemia, limit alcohol and have tea, coffee, or milk at a different time from iron-rich meals or iron supplements. Heavy alcohol use can increase your risk of anemia and lower your folate levels. Tea, coffee, and milk can make it harder for your body to absorb iron.
Yes, most people with anemia can live a normal life when the underlying cause is treated. Anemia caused by low iron, vitamin B12, or folate usually improves with proper treatment. Some types of anemia are long-term and require ongoing treatment.
