Hypoproteinemia is the medical term for lower-than-normal levels of protein in your body. Symptoms include swelling in your legs, face, and other areas, loss of muscle mass, and dry, brittle hair that falls out.

Protein is an essential nutrient found in almost every part of your body — including your bones, muscles, skin, hair, and nails.

Protein keeps your bones and muscles strong. It makes up a molecule called hemoglobin, which carries oxygen throughout your body. It also makes up chemicals called enzymes, which cause the many reactions that keep your organs working.

You get protein from foods like red meat, chicken, fish, tofu, eggs, dairy, and nuts. You need to eat protein every day because your body does not store it.

A lack of enough protein can cause problems such as:

  • muscle loss
  • slowed growth
  • weakened immune system
  • weakened heart and lungs

A severe protein deficiency can be life threatening.

Symptoms of hypoproteinemia include:

  • swelling in the legs, face, and other parts of the body from fluid buildup
  • loss of muscle mass
  • dry, brittle hair that falls out
  • lack of growth in children
  • cracked, pitted nails
  • infections
  • fatigue

There are several reasons why your body may be low on protein.

Not enough protein in your diet

You can become deficient in protein if you don’t eat enough food sources. Severe protein deficiency is called kwashiorkor. This condition is more common in low income countries where people don’t have enough to eat.

Some people do not consume enough protein in their diet, possibly due to dietary choices or aversions. This may also occur in people with dementia, as they are more likely to be unable to feed themselves and therefore are much more likely to become protein-deficient.

Your body can’t properly absorb protein from the foods you eat

A problem absorbing protein from foods is called malabsorption. Possible causes include:

  • celiac disease
  • Crohn’s disease
  • parasites and other infections
  • damage to your pancreas
  • defects in your intestines
  • surgery, including weight loss surgery or procedures that remove part of your intestines

Liver damage

Your liver makes a protein called albumin, which makes up about 60 percent of the total protein in your blood. Albumin carries vitamins, hormones, and other substances throughout your body.

It also prevents fluid from leaking out of your blood vessels (which is why fluid builds up in your body when you’re low in protein). Damage to your liver prevents it from making albumin.

Kidney damage

Your kidneys filter waste products from your blood. When your kidneys are damaged, wastes that should be filtered out remain in your blood. Substances like protein, which need to stay in your blood, leak into your urine. An excess of protein in your urine due to kidney damage is called proteinuria.

You can treat low protein in your diet by increasing the amount of protein you eat. Foods that are good sources of protein include:

  • red meat
  • poultry
  • fish
  • tofu
  • eggs
  • beans and other legumes
  • nuts
  • dairy foods like milk and yogurt

Children in low income countries who have kwashiorkor are treated with ready-to-use therapeutic food (RUTF), which is made from:

  • peanut butter
  • milk powder
  • sugar
  • vegetable oil
  • vitamins and minerals

Other treatments depend on the cause of low protein and may include:

  • antibiotics or antiparasitic drugs to treat infections
  • vitamin and mineral supplements to treat any other nutrient deficiencies
  • a gluten-free diet to treat damage to your intestines from celiac disease
  • steroids, immune system suppressors, and other drugs to bring down inflammation in your intestines
  • medications or surgery to treat liver damage
  • dialysis or a kidney transplant to treat kidney disease

If you have a problem absorbing protein from the foods you eat, your doctor will treat the condition that’s causing the poor absorption.

Some women develop protein deficiency in pregnancy due to:

  • severe nausea and vomiting that prevents them from eating a normal diet
  • a vegetarian or vegan diet that’s low in protein
  • inability to afford to eat a well-balanced diet

During pregnancy, you need extra protein and other nutrients to supply both your own body and that of your growing baby. The Institute of Medicine (IOM) recommends that you get an extra 25 grams of protein daily starting in the second trimester of your pregnancy.

You can prevent hypoproteinemia by getting enough protein in your diet. The recommended daily allowance of protein (RDA) is 0.8 grams of protein for every kilogram of body weight.

So if you weigh 150 pounds, you’ll need about 54 grams of protein daily. (This number can vary slightly based on your gender and activity level.)

If you’re vegetarian or vegan, you can increase your protein intake by eating more plant-based sources of protein, such as:

  • soy milk
  • tofu
  • tempeh
  • beans
  • legumes (lentils, peas)
  • nuts (walnuts, almonds, pistachios)
  • nut butters
  • whole-grain bread

If you have a condition like liver disease, kidney disease, infection, celiac disease, or Crohn’s disease, follow your doctor’s recommended treatment. Treating underlying conditions can help improve your body’s ability to absorb protein and other nutrients from food.

Severe protein deficiency is rare in higher-income countries like the United States. However, you can still experience a drop in your protein level if you don’t include enough of this important nutrient in your diet or your body can’t properly absorb protein from the foods you eat.

Work with your doctor and a dietitian to help make sure you’re getting the right balance of nutrients in your diet.