Understanding Anemia -- Diagnosis and Treatment

Medically Reviewed by Sabrina Felson, MD on May 29, 2023
8 min read

To diagnose anemia, your doctor will likely ask you about your medical history, perform a physical exam, and order blood tests.

You can help by providing detailed answers about your symptoms, family medical history, diet, medications you take, alcohol intake, and ethnic background. Your doctor will look for symptoms of anemia and other physical clues that might point to a cause.

There are basically three different causes of anemia: blood loss, decreased or faulty red blood cell production, or destruction of red blood cells.

Blood tests will not only confirm the diagnosis of anemia, but also help point to the underlying condition. Tests might include:

  • Complete blood count (CBC), which determines the number, size, volume, and hemoglobin content of red blood cells
  • Blood iron level and your serum ferritin level, the best indicators of your body's total iron stores
  • Levels of vitamin B12 and folate, vitamins necessary for red blood cell production
  • Special blood tests to detect rare causes of anemia, such as an immune attack on your red blood cells, red blood cell fragility, and defects of enzymes, hemoglobin, and clotting
  • Reticulocyte count, bilirubin, and other blood and urine tests to determine how quickly your blood cells are being made or if you have a hemolytic anemia, where your red blood cells have a shortened life span

Only in rare cases will a doctor need to remove a sample of bone marrow to determine the cause of your anemia.

Your doctor may not treat your anemia until the underlying cause has been established. The treatment for one type of anemia may be both inappropriate and dangerous for another type of anemia.

Anemia Caused by Blood Loss
If you suddenly lose a large volume of blood, you may be treated with fluids, a blood transfusion, oxygen, and possibly iron to help your body build new red blood cells. Chronic blood loss is treated by identifying the source of bleeding, stopping the bleeding, and, if necessary, providing treatment for iron-deficiency anemia.

Anemia Caused by Decreased Red Blood Cell Production
The type of treatment you receive depends on the cause of decreased red blood cell production.

Anemia Caused by Iron Deficiency
Without adequate iron, the body is unable to produce normal red blood cells. In young women, iron deficiency anemia can result from heavy menstrual bleeding. Non-menstruating women or men who develop iron deficiency need to have a colon exam (colonoscopy or barium enema) to help identify the source of chronic bleeding.

With iron deficiency anemia, your doctor will probably recommend iron supplements that contain the ferrous form of iron. Timed-release iron supplements are not a good choice for most people, because iron is primarily absorbed in the upper part of the digestive tract. If you use iron supplements, remember the following cautions:

  • Always consult with your doctor before taking iron supplements. Excess iron intake can be harmful. Symptoms of iron overload include fatigue, vomiting, diarrhea, headache, irritability, heart disease, and joint problems.
  • Iron supplements -- like all supplements and any medication -- should be kept out of the reach of children. Iron poisoning is one of the most common causes of accidental poisoning in young children. It can prove fatal in a matter of hours. Symptoms of poisoning in a child include dizziness, confusion, nausea, vomiting, and diarrhea. Seek medical help immediately.
  • Watch for side effects. You may need to continue taking iron supplements for up to one year. Taking iron supplements with food can help prevent common side effects, which may include nausea, diarrhea, constipation, and stomach pain. Let your doctor know if you continue to have side effects. Different formulations are available.
  • Watch for drug interactions. Tell your doctor if you are being treated for another condition. For example, calcium supplements interfere with iron absorption, so it is best to take them at different times of the day.
  • The body absorbs iron best when taken in a mildly acidic medium, so your doctor may suggest taking iron with a half-glass of orange juice or with vitamin C.

Your doctor may also recommend that you increase the amount of iron in your diet. Good dietary sources of iron include red meat, beans, egg yolk, whole-grain products, nuts, and seafood. Many processed foods and milk are also reinforced with iron.

Your doctor will monitor your red blood cell counts, including hematocrit, hemoglobin, and ferritin levels, during treatment. If your anemia doesn't improve with iron supplements, your doctor will look for some other underlying cause. In rare cases, your doctor may prescribe iron injections or give you iron intravenously (through a needle in the vein). In extremely rare cases of life-threatening iron-deficiency anemia, treatment may involve a blood transfusion.

Anemia Caused By Vitamin B12 and Folate Deficiency

Treatment depends on the cause of the deficiency. If your body stores are depleted of vitamin B12, your doctor will most likely prescribe vitamin B12 injections. Vitamin B12 can also be given by mouth, but very high doses are needed. Vitamin B12 can also been given under the tongue or in a nasal spray, but these preparations are expensive and have not been adequately studied to be recommended. There is a good chance that many of the symptoms of deficiency will improve once the body is provided with the needed B12.

Some people with vitamin B12 deficiency have a permanent inability to absorb vitamin B12 and will need injections every one to three months or pills daily for the rest of their lives.

Some forms of gastric bypass surgery are associated with deficiencies of iron, vitamin B12, and other nutrients typically absorbed in the part of the stomach that is bypassed.

Your doctor may also recommend that you increase the amount of vitamin B12 in your diet. Good dietary sources of vitamin B12 are meat, liver, and kidney; fish, oysters, and clams; and milk, cheese, and eggs.

If you have a folate deficiency (which is rare), your doctor will prescribe folic acid supplements (folic acid is a form of folate used in dietary supplements and fortified foods.) They may recommend you to increase the amount of folate in your diet. Good dietary sources of folate include fresh fruits, green leafy vegetables, and cruciferous vegetables (cauliflower, broccoli, and Brussels sprouts); dairy products; and whole grain cereals. Vegetables should be eaten raw or lightly cooked.

Anemia Caused by Problems of the Bone Marrow and Stem Cells.

This anemia tends to be more persistent and difficult to treat. The treatments for hereditary anemias, such as thalassemia or sickle cell disease, vary widely and depend on the specific condition and the severity of symptoms. Some anemias will not require any treatment, while others may require repeated transfusions and other aggressive measures. Although aplastic anemia will occasionally go into spontaneous remission, some people with this disorder require bone marrow transplantation.

Anemia Caused by Chronic Disease

It is best to treat the underlying condition whenever possible. Anemia caused by chronic kidney disease or following chemotherapy can often be treated with an injection of recombinant human erythropoietin called darbepoetin alfa (Aranesp).or epoetin alpha (Epogen, Procrit). Erythropoietin is a hormone that stimulates the production of red blood cells in the bone marrow. Darbepoetin alfa is a synthetic form of erythropoietin.

Anemia Caused by Increased Red Blood Cell Destruction
The treatment of hemolytic anemia will be tailored to the underlying cause. Mild cases of hemolytic anemia may not require any treatment at all. If an offending environmental agent can be identified -- a chemical, for example -- exposure to this agent should stop immediately. Other people with hemolytic anemia may need surgery to replace faulty heart valves, remove a tumor, or repair abnormal blood vessels.

Supportive treatment -- like intravenous fluids and pain medication -- will often be given. A blood transfusion may be necessary in some cases. Steroids can halt the body's immune attack on its own red blood cells. Certain damaging factors can be removed from the blood by a treatment called plasmapheresis.

If hemolytic anemia persists despite treatment, your doctor may recommend splenectomy -- surgical removal of the spleen -- as a last resort. Most people can lead a normal life without their spleen.

Longstanding hemolytic anemia can cause gallstones to develop from the by-products of red blood cell destruction. Gallbladder surgery may be necessary for symptomatic gallstones. A type of hemolytic anemia that occurs more commonly in children is associated with kidney damage, and dialysis may be necessary. In extremely rare cases, bone marrow transplantation may be the only solution for certain types of hemolytic anemia.

Sickle Cell Anemia
Occasionally, children with sickle cell disease who have an appropriate donor may be cured by a bone marrow transplant. Alternatively, a drug called hydroxyurea (DroxiaHydrea, Silkos) appears to stimulate the formation of an alternate form of hemoglobin that isn't susceptible to the sickling, and may be used to reduce the frequency of bone pain. The bone pain can usually be eased with pain medications and the anemia may require transfusions. Hydroxyurea may also decrease the need for blood transfusions.

Lead poisoning is treated by discontinuing exposure to lead and administering a drug that binds and draws lead out of the body.

You can help prevent iron-deficiency anemia by eating a well-balanced diet that includes good sources of iron, vitamin B12, and folate. Steps to take include the following:

  • If you are a vegetarian or vegan, talk to your doctor or a nutritionist about your diet and any possible need for supplements.
  • Ask your doctor or nutritionist if you should take vitamin C. Vitamin C makes the stomach more acidic and may improve the absorption of iron in your diet.
  • Decrease your consumption of caffeinated products and tea. These substances can decrease iron absorption. Other offenders include fiber, large amounts of calcium, and the phytates found in some vegetables.
  • Select iron-fortified cereals and breads.
  • Carefully follow safety guidelines if your occupation involves work with lead-containing materials such as batteries, petroleum, and paint.
  • Ask your doctor or local public health authorities about getting your dishes and other eating utensils tested for lead.