Low Hemoglobin Levels: Everything You Need to Know

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Low hemoglobin levels can be caused by a diet low in iron, gastrointestinal (GI) bleeding, GI surgery, and heavy menstrual bleeding, among other things.

Hemoglobin is a protein in your red blood cells that transports oxygen from your lungs to the rest of your body and removes carbon dioxide from the lungs.

Some of the symptoms related to low hemoglobin include body aches, chest pain, weakness, fast heartbeat, and shortness of breath.

This article will review the causes, symptoms, and treatment of low hemoglobin and will describe what you can do to help prevent low hemoglobin levels.

Young woman who appears tired and has a headache.

VioletaStoimenova / Getty Images

Causes of Low Hemoglobin Levels

There are several possible reasons why you have low hemoglobin.

Bleeding Problems

Some examples of bleeding problems that can lead to low hemoglobin include:

  • Heavy menstrual bleeding
  • Ongoing bleeding in your (GI) tract from colon cancer or an ulcer
  • Bleeding in your gastrointestinal tract caused by the overuse of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) like Aleve (ibuprofen).

Problems with Red Blood Cell Production

Your body produces red and white blood cells in your bone marrow. But your body may not make enough red blood cells if you have conditions that affect your bone marrow’s ability to produce or support enough red blood cells. Examples include:

Sometimes your body produces enough red blood cells, but the cells are dying faster than your body can replace them. Conditions where this happens include:

Low Nutrient Intake

You may have low hemoglobin if:

  • Your body can’t absorb iron, which affects your body’s ability to make red blood cells.
  • Your diet is low in iron. You get iron from the foods you eat, and even though not all of the iron is absorbed by your body, a diet low in iron can lead to iron deficiency anemia.
  • You’re not getting enough essential nutrients like vitamins B12 and B9, which can lead to pernicious anemia and megaloblastic anemia.

Other Causes

Other reasons you might have low hemoglobin levels include:

  • Recent gastrointestinal (GI) surgery that caused your body to poorly absorb iron
  • Donating a lot of blood
  • Major changes to your body, such as a pregnancy or, in children, a growth spurt

Low Hemoglobin Levels in Infants

Newborns can have temporary anemia at six to nine weeks if they haven't made enough new red blood cells and have used up the ones they were born with. This anemia usually resolves on its own.

Babies can also have anemia from breaking down red blood cells too quickly if the mother and baby have different blood types.

However, most newborns have sufficient iron stored in their bodies for about the first six months of life. After six months they need an additional source because breast milk doesn't contain enough iron. Iron-rich foods, iron-fortified cereals, iron-fortified formula, or iron supplement drops can be added to the baby's diet to help prevent low hemoglobin levels in infants.

There Are Different Types of Anemia

Iron deficiency anemia is just one type of anemia. Pernicious anemia, aplastic anemia, and hemolytic anemia are some of the other types.

What Are the Symptoms of Low Hemoglobin?

Symptoms of low hemoglobin include:

  • Body aches
  • Brittle nails
  • Chest pain
  • Feeling dizzy or fainting
  • Feeling weak
  • Having cold hands and feet
  • Having a fast heartbeat
  • Having a sore or swollen tongue
  • Headache
  • Irritability
  • Pale skin
  • Shortness of breath
  • Trouble concentrating
  • Trouble sleeping
  • Wanting to eat items like dirt or ice

Risk Factors for Low Hemoglobin

Some people are at greater risk for low hemoglobin. They include:

  • Infants ages 6–12 months
  • Children with lead in their blood (which blocks the body's ability to make hemoglobin)
  • Teens
  • Adults aged 65 and older
  • People with cancer, celiac disease, or chronic kidney disease
  • People with a genetic blood disorder
  • Pregnant people
  • People with heavy bleeding during their periods
  • Vegetarians or vegans

How Are Hemoglobin Levels Tested?

The symptoms of low hemoglobin are similar to the symptoms caused by many other medical problems. That's why it is important to see your healthcare provider if you have these symptoms to determine the true cause.

To help diagnose and then treat low hemoglobin, your healthcare provider will order a blood test called a complete blood count (CBC) that can measure your hemoglobin level and red blood cells. They will likely perform a physical exam and other diagnostic tests as well.

Normal, Low, and High Hemoglobin

You can find out your hemoglobin level through a blood test. The result will indicate whether your hemoglobin level is normal, low, or high:

  • Normal hemoglobin level: 13.2–16.6 grams per deciliter (g/dL) for males and 11.6–15 g/dL for females
  • Low hemoglobin level: Any levels lower than 13.2–16.6 g/dL for males and 11.6–15 g/dL for females
  • High hemoglobin level: Any levels higher than 13.2–16.6 g/dL for males and 11.6–15 g/dL for females

Dangerously Low Hemoglobin Levels

A hemoglobin level of less than 13.5 gm/dL for men and 12 gm/dL for women is considered severely low. A hemoglobin level of less than 5.0 grams per deciliter (g/dl) is very dangerous and could lead to heart failure or death.


Treatment of low hemoglobin will depend on your age, the severity of your low hemoglobin, and the cause. For iron deficiency anemia in particular, there are a few treatments available, including:

  • Iron supplements taken orally a couple of times a day: This is the most common treatment for iron deficiency. Always check with your healthcare provider before using iron supplements. Let them know if you experience side effects, such as vomiting or diarrhea.
  • Iron therapy that delivers iron through a blood vessel: This is more common for severe iron deficiency anemia. It also is more commonly used in those with iron deficiency anemia who also have chronic conditions such as celiac disease or kidney disease.
  • Red blood cell transfusions: These can raise the number of red blood cells and iron in your blood.
  • Surgery that stops the bleeding that is leading to iron deficiency anemia: Your healthcare provider also may perform procedures like an upper endoscopy (EGD) or colonoscopy to find the cause of bleeding.

Your healthcare provider may also talk to you about adding more iron-rich foods to your diet. These include:

  • Beans and legumes
  • Fish
  • Leafy greens like collards and kale
  • Meat
  • Poultry like chicken and turkey
  • Tofu

Consuming more foods that are rich in vitamin C, such as citrus fruits, can improve your iron absorption.

Preventing Low Hemoglobin Levels

It isn't always possible to prevent low hemoglobin. When you have preventable iron deficiency anemia, the most effective preventive moves include:

  • Consuming more foods with iron: Most people with iron deficiency need 150–200 milligrams (mg) per day of iron.
  • Making healthy food choices in general: Eating foods like leafy green vegetables (such as kale, spinach, and romaine lettuce), beans, and lean proteins helps your body to get iron and other vitamins that it needs.
  • Talking to your healthcare provider if you experience unusual blood loss: This can include heavy periods or blood in your stool.
  • Talking to your healthcare provider if you use calcium pills: This is because the body has a harder time absorbing iron with calcium. Your healthcare provider may suggest another way to get calcium.


There are several causes of low hemoglobin related to problems with bleeding, red blood cell production, nutrient intake and absorption, and others. Symptoms of low hemoglobin include headaches, fatigue, fast heartbeat, and pale skin.

Treatments for low hemoglobin include iron supplements, iron therapy, blood transfusion, surgery, and treating the underlying condition causing low hemoglobin levels. Adding more iron-rich foods to your diet is also important if you have iron deficiency anemia.

If you have low hemoglobin, work with your healthcare provider to determine what is causing it and find a treatment plan to help you manage it.

Frequently Asked Questions

  • What does it mean if your hemoglobin levels are low?

    It means that your blood will have trouble carrying oxygen throughout your body and getting rid of carbon dioxide. Low hemoglobin can be associated with certain illnesses and conditions, like anemia. Iron deficiency anemia is the most common form of anemia. This means your body does not have enough iron.

  • How can you raise your hemoglobin levels?

    You can raise your hemoglobin levels by eating more foods that have iron, like poultry, meat, tofu, and leafy greens like spinach and kale. If your hemoglobin level is particularly low, your healthcare provider may recommend iron supplements or iron therapy.

14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Vanessa Caceres
Vanessa Caceres is a nationally published health journalist with over 15 years of experience covering medical topics including eye health, cardiology, and more.