Hyperemia is more blood than normal going to your body’s tissues or organs. This can have normal causes or causes that mean something’s wrong. You don’t need treatment for certain types of hyperemia, but you do for others. Treatments usually consist of over-the-counter medicines or prescription drugs.


Normal blood flow compared to the increased blood flow of hyperemia.
Hyperemia is a higher blood flow than normal in response to something happening in your body that increases its demand for blood.

What is hyperemia?

The hyperemia definition is blood flow that’s higher than usual. Normally, the small blood vessels (arterioles) in your organs send just the right amount of blood to your organs. Similar to adjusting the sprayer setting on a garden hose attachment, arterioles can control how much blood goes to your tissues.

But sometimes, your cells and tissues need more blood than usual. In that case, it’s a good thing when your body can meet that higher demand.

In other cases, a higher-than-normal demand for blood can indicate something’s wrong. In those situations, hyperemia is a symptom and a sign that offers clues to your healthcare provider.

Types of hyperemia

Types of hyperemia include:

  • Reactive hyperemia (high blood flow after something limited your blood flow).
  • Active hyperemia (high blood flow to meet active muscles’ increased need for oxygen).
  • Functional hyperemia (high blood flow going to active neurons in your brain).
  • Conjunctival hyperemia (high blood flow from inflammation in your eye).

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What does hyperemia feel like?

Often, you won’t even realize hyperemia is happening. It helps your muscles and neurons get the oxygen they need. But when blood rushes to your skin, it can feel warm. And when you release something that’s restricting normal blood flow in your arm or finger, it might tingle. When a lot of blood goes to your eye, the white part of your eye looks red.

Your body releases substances (nitric oxide, prostaglandins, adenosine and potassium) that make your blood vessels open more. Providers can use some of these substances to imitate the effects of exercise, such as during a stress test.

Possible Causes

What are the most common causes of hyperemia?

Causes of hyperemia include:

Something limits your blood flow, causing a period of low blood flow. High blood flow happens when your remove the restriction.
You remove the dental floss you wrapped around a finger.
Reactive hyperemia.
A lack of estrogen during menopause.
Blood flow to your skin increases during a hot flash.
Reactive hyperemia.
Blood flow increases when your muscles are moving. Moving muscles demand more oxygen and nutrients.
You run through the airport to catch your flight.
Active hyperemia or exercise hyperemia.
During increased brain activity, blood flow increases around active neurons in your brain to make sure they have enough oxygen and nutrients.
You’re trying to solve a problem.
Functional hyperemia.
Blood vessels dilate because of inflammation due to allergies, fatigue, infections, eye irritants or other conditions. Hyperemia in your eye’s conjunctiva makes the white part of your eye look red.
You have pink eye.
Conjunctival hyperemia.

Care and Treatment

How do providers assess hyperemia?

Based on the type of hyperemia, providers or researchers can use different methods to assess it. These methods include:

  • Ultrasound.
  • Near-infrared spectroscopy (a noninvasive way to see how much blood is getting to an organ).
  • Peripheral artery tonometry (a noninvasive way to check vascular function in your fingers).
  • Arterial spin labeling (a way to use magnetic resonance imaging, or MRI, to measure how much blood is getting to your brain’s tissues).
  • Imaging of the eye for conjunctival hyperemia.

Because some kinds of hyperemia don’t need treatment, researchers may use some of these methods more often than healthcare providers who take care of people on a daily basis.

How is hyperemia treated?

You don’t need hyperemia treatment for the functional or active types. You may need treatment for other types of hyperemia, like hormone therapy, antidepressants or gabapentin for hot flashes (vasomotor symptoms) from menopause.

People with conjunctival hyperemia need treatment for what caused it. They may need treatment for:

What can I do at home to treat hyperemia?

When you have hyperemia from a hot flash due to menopause, you can remove a layer of clothing or drink ice water. Having a small fan nearby helps if hot flashes are frequent.

For conjunctival hyperemia from allergies that affect your eyes, you can try over-the-counter (OTC) allergy medicines. If they don’t work, you may need a prescription for an allergy medicine. For mild cases of keratitis, you can use lubricant eye drops. Other people with keratitis need a prescription.

While you don’t need to treat subconjunctival hemorrhage, you can use artificial tears for it.

You’ll need a prescription for medicines that treat most other eye issues that cause hyperemia.

What are the possible complications or risks of not treating hyperemia?

Without treatment, some conditions that cause conjunctival hyperemia — like glaucoma, uveitis and keratitis — can lead to vision loss.


Can hyperemia be prevented?

You can help prevent conjunctival hyperemia by avoiding the allergen that causes it. Protecting your eyes and keeping your contact lenses clean can help prevent keratitis and subconjunctival hemorrhage.

When To Call the Doctor

When should hyperemia be treated by a doctor or healthcare provider?

If you’re having frequent hot flashes that are bothersome, talk to your healthcare provider about possible medical treatments. If you have redness in the whites of your eyes, contact your provider for an eye exam. They can tell you if you have an eye condition that requires treatment and/or a prescription.

A note from Cleveland Clinic

In many cases, hyperemia isn’t a cause for concern, as it’s generally a natural response of your body. However, if you have red in the whites of your eyes, you can give yourself peace of mind by seeing a healthcare provider. If they give you a prescription, be sure to follow the instructions for using it. In addition to following the schedule they give you, make sure to wash your hands before putting drops in your eyes.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 05/14/2023.

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