Anemia, or a low hemoglobin level, is one of the most common problems seen in primary care. Hemoglobin is a protein found within red blood cells (RBCs) that contains iron.

Anemia can occur as the result of too few normal RBCs, a normal cell number with low hemoglobin levels in each cell, or hemoglobin that’s genetically altered.

First-line treatments for anemia depend on the cause.

Normal cell numbers with low cellular hemoglobin means you may not have enough iron, vitamin B12, or folate, all of which are necessary for your bone marrow to make RBCs.

Low iron levels can also be from blood loss, for example from monthly periods. Replacing these nutrients usually fixes the anemia easily.

Too few but normal RBCs can occur as a result of taking medications that suppress RBC production. Stopping or lowering the dose usually helps. Sometimes a chronic condition, like heart failure, is the cause.

RBCs live in the blood about 120 days, then are broken down and the hemoglobin is recycled. If this is happening faster than cells are being made, looking at a blood smear or the bone marrow under a microscope may be the next step to determine a cause and treatment.

The treatment isn’t working if your symptoms don’t improve. Tiredness is a common symptom, and sometimes shortness of breath with mild exercise can occur as well. This is because the main function of the RBCs is to take oxygen from the lungs to other parts of the body

Not enough oxygen in the tissues means that your muscles may tire too quickly or your thinking may be cloudy. In severe cases, your heart may not beat correctly.

Follow-up blood tests are the first step. That may include:

  • a complete blood count (CBC), which checks your hemoglobin level and RBC number
  • follow-up iron, vitamin 12, or folate studies if the cause of your anemia is known
  • a test to look for increased RBC production, known as a reticulocyte count, to see if your bone marrow is doing its job
  • a peripheral blood smear to look for too-fast recycling of blood cells may also be ordered
  • a hemoglobin electrophoresis test to look for genetic hemoglobin protein problems

Sometimes the low iron level is from blood loss in the gut that isn’t obvious. Your provider may also want to check your stool for microscopic amounts of blood, in case you’re bleeding and don’t know it.

Sometimes people can’t absorb oral iron or vitamins, or they don’t take enough consistently to fix the problem.

Prescription and over-the-counter medications may also interfere with absorption of supplements. Intravenous iron and vitamin B12 shots are also available.

The next step would be a complete physical looking for a chronic disease. This would include screening tests tailored to you, if they haven’t already been done.

If the anemia persists, or you’re over 50 years old, an endoscopy may be recommended to look in the stomach or colon for persistent microscopic blood loss.

If the anemia becomes severe, a blood transfusion or a referral to a blood specialist, known as a hematologist, may be needed.

Oral iron supplements are the first-line anemia treatment, along with a diet high in iron, which can be found in dark green leafy vegetables.

However, constipation from iron supplements is common. Be sure to also follow a diet that’s high in fiber.

Iron supplements may be better tolerated, and are equally effective, if taken only three times a week.

Food helps with any nausea and supports iron absorption.

If you need intravenous iron, you’ll be monitored closely while it’s being given in case of an allergic reaction.

The main risk of untreated or undertreated anemia is not getting enough oxygen to vital organs like the brain, heart, or kidneys. There are also risks specific to pregnancy.

Without proper treatment, some patients feel that their thinking is a bit cloudy, or they’re more forgetful. Tiredness is a common complaint.

Symptoms of severe anemia include shortness of breath at rest, lightheadedness, or chest pain. See your doctor immediately if you experience these symptoms because they can be life threatening.

The most common cause of anemia is low iron in the body and blood. If this is the cause, then eating iron-rich foods can certainly help. Iron, however, is absorbed best from food and best in younger people.

Antacids can interfere with iron absorption, while taking vitamin C (ascorbic acid) can help.

Taking iron supplements three times a week can also help. If you get nausea or severe constipation with iron supplements, try one with a lower iron content, or a liquid form, and take it with food.

In extreme or resistant cases, iron can also be given intravenously.

If the anemia is not related to iron or vitamin levels, then increasing your iron intake won’t help, and it can lead to problems related to too much iron in the body.

This depends on the severity and cause of the anemia.

If the cause is low iron, your doctor will check your CBC and iron studies after a month. Iron levels should be back to normal after 2 to 4 months of supplementation. Vitamin B12 and folate levels also take that long to fully respond.

For other causes of anemia, your provider will likely discuss next steps for treatment and monitoring with you.

No preparation is necessary for any blood testing that might be ordered. If a procedure such as an endoscopy has been ordered, the doctor performing the procedure will give you detailed instructions on how to prepare.

It’s generally best to stick with the same healthcare provider with whom you started this journey.

If your symptoms persist, or the treatments aren’t working, your provider can do further testing. They can also refer you to a specialist who can help you discover and treat the root cause of the anemia.


Dr. Meredith Goodwin is a board certified family medicine physician, practicing in Sacramento, California. She has broad experience with full-spectrum family medicine, including home visits, telehealth, veteran’s care, patient advocacy, and life care planning. She received her MD from Columbia University College of Physicians and Surgeons in New York, and completed her Family Medicine residency at UCLA. She is a Fellow of the American Academy of Family Physicians (FAAFP).