Hyperemia is an increased amount of blood in the vessels of an organ or tissue in the body.

It can affect many different organs, including the:

  • liver
  • heart
  • skin
  • eyes
  • brain

Types of hyperemia

There are two types of hyperemia:

  • Active hyperemia happens when there’s an increase in the blood supply to an organ. This is usually in response to a greater demand for blood — for example, if you’re exercising.
  • Passive hyperemia is when blood can’t properly exit an organ, so it builds up in the blood vessels. This type of hyperemia is also known as congestion.

Each type of hyperemia has a different cause.

Active hyperemia is caused by an increased flow of blood into your organs. It usually happens when organs need more blood than usual. Your blood vessels widen to increase the supply of blood flowing in.

Causes of active hyperemia include:

  • Exercise. Your heart and muscles need more oxygen when you’re active. Blood rushes to these organs to supply extra oxygen. Your muscles need up to 20 times their normal supply of blood during a workout.
  • Heat. When you’re running a high fever or it’s hot outside, extra blood flows to your skin to help your body release heat.
  • Digestion. After you eat, your stomach and intestines need more blood to help them break down foods and absorb nutrients.
  • Inflammation. During an injury or infection, blood flow to the site increases.
  • Menopause. Women who are in menopause often have hot flashes, which causes a rush of blood to the skin — especially of the face, neck, and chest. Blushing is a similar response.
  • Release of a blockage. Hyperemia can happen following ischemia, which is poor blood flow to an organ. Once ischemia is treated, blood rushes to the area.

Passive hyperemia happens when blood can’t properly drain from an organ and begins to build up in the blood vessels.

Causes of passive hyperemia include:

  • Heart failure or ventricular failure. The left and right ventricles are the two main pumping chambers of the heart. The right ventricle pumps blood to the lungs, and the left ventricle pumps oxygen-rich blood to the body. When the heart can’t beat well enough to push blood through the body, blood begins to back up. This backup causes swelling, or congestion, in organs like the liver, lungs, spleen, and kidneys.
  • Deep vein thrombosis (DVT). DVT is caused by a clot in one of the deep veins — often in your lower legs. The clot can break free and get lodged in a vein in your lung, called a pulmonary embolism.
  • Hepatic vein thrombosis (HVT), also called Budd-Chiari syndrome. HVT is a blockage in the veins of the liver caused by a blood clot.

The main symptoms of hyperemia are:

  • redness
  • warmth

Other symptoms depend on the cause of the problem.

Heart failure symptoms include:

  • shortness of breath
  • coughing or wheezing
  • swelling in the belly, legs, ankles, or feet caused by fluid buildup
  • fatigue
  • loss of appetite
  • nausea
  • confusion
  • fast heartbeat

DVT symptoms include:

  • swelling and redness in the leg
  • pain
  • warmth

HVT symptoms include:

  • pain in the upper right side of your abdomen
  • swelling in your legs and ankles
  • cramps in your legs and feet
  • itching

Hyperemia itself isn’t treated, because it’s just a sign of an underlying condition. Active hyperemia caused by exercise, digestion, or heat doesn’t need to be treated. The blood flow will slow down once you stop exercising, your food is digested, or you get out of the heat.

Causes of passive hyperemia can be treated. Doctors treat heart failure by addressing the cause of the disease, such as high blood pressure and diabetes.

Treatments include:

DVT is treated with blood thinners such as heparin or warfarin (Coumadin). These drugs stop the blood clot from getting bigger, and prevent your body from making new clots. If these drugs don’t work, you might get clot-busting drugs called thrombolytics to quickly break up the clot. You can also wear compression stockings to stop the swelling in your legs from DVT.

HVT is also treated with blood thinners and clot-busting drugs. You might need medication to treat liver disease, too.

Hyperemia itself doesn’t cause complications. Conditions that cause hyperemia can have complications like:

  • heart valve problems
  • kidney damage or failure
  • heart rhythm problems
  • liver damage or failure
  • pulmonary embolism — a blood clot that becomes lodged in a blood vessel in the lung

The outlook depends on the cause of increased blood in the blood vessels.

Heart failure is a chronic condition. Although you can’t cure it, you can manage its symptoms with medication and changes to your lifestyle. DVT can be treated, but you’ll need to watch for symptoms because it can come back in the future.