What Is Compartment Syndrome, and How Do I Know If I Have It?

Compartments are spaces in your body that contain muscles, nerves, and blood vessels. Certain injuries can cause bleeding into a compartment, which increases the pressure there. If the pressure is high enough, it can prevent the muscles from getting proper blood supply. Muscle tissue can die when it doesn’t get enough blood and oxygen. This is why compartment syndrome is a medical emergency. 

Here we’ll discuss what you need to know about compartment syndrome, including symptoms, diagnosis, and treatment.

What is compartment syndrome? 

Thick tissue (fascia) works as a sort of wall that divides your arms and legs into compartments. These tissues can’t stretch, so high pressure in a compartment prevents normal blood flow to everything within that compartment. “Compartment syndrome” occurs when high pressure affects blood flow within a compartment.

If high pressure within a compartment doesn’t get relief in time, the lack of blood flow causes the muscles to die. This is called “necrosis.” And it leads to disability because necrosis is irreversible. 

Compartment syndrome most commonly occurs in the lower leg, which has four compartments. The forearm and upper arm have two compartments, although some experts say there are three. The upper leg (thigh) and hand also have compartments, but compartment syndrome in these areas is less common.

What are the signs and symptoms?

The primary symptom of compartment syndrome is pain, which can be severe and uncontrollable. It’s usually “out of proportion to the injury,” meaning the pain is greater than what you would expect from the injury. Paresthesias, such as numbness or tingling, can also occur in the affected limb.

The “five P’s” is one way to help you remember the common signs and symptoms of compartment syndrome:

1.  Pain

2.  Pallor (lack of color) 

3.  Paresthesias (numbness, tingling, pins and needles)

4.  Pulselessness (weak or absent pulse in the affected area)

5.  Paralysis (weakness)

Loss of pulses and muscle paralysis are later findings in compartment syndrome. When these occur, it may mean there’s already some damage.

What causes compartment syndrome?

Usually some sort of injury causes compartment syndrome. In these cases, bleeding into the compartment causes the pressure to rise. Some examples include:

• Fracture

• Powerful blow to a limb

• Muscle tear

• Crush injury

Compartment syndrome can also occur if a cast is too tight or after a procedure to repair a blood vessel. 

“Chronic exertional compartment syndrome” is a different type of compartment syndrome. Vigorous exercise causes it, and it commonly occurs in the leg. The good news is that it’s a less severe problem, so it’s not usually an emergency. But it may require surgery if nonoperative treatments don’t work.

How do you diagnose compartment syndrome?

Your healthcare provider can often make the diagnosis of compartment syndrome by discussing the history of your injury and examining you. If you have severe pain when they stretch your muscles in the affected compartment, that’s a sign of compartment syndrome. 

In some cases, it’s necessary to measure the pressure in the compartment. It can help in cases where a person is unconscious (for example, with a traumatic injury) or can’t assist in the examination. It’s also useful when a provider suspects chronic exertional compartment syndrome. 

To measure the pressure in a compartment, your provider will use a pressure monitor, which comes in a kit with a needle and syringe. After inserting the needle into the compartment, this kit measures the pressure within. Specialists use the delta measurement to figure out if surgery is necessary. The delta is the difference between your diastolic blood pressure and the compartment pressure. Your provider will diagnose compartment syndrome and recommend surgery if the difference is 30 mmHg or less.

How do you treat it?

Compartment syndrome can lead to permanent damage if it doesn’t get treatment in time. So it requires emergency surgery. A surgeon cuts open the “walls” dividing the compartments to relieve the pressure in them. This is a fasciotomy procedure. 

The number of compartments that need to be released depends on the limb that’s affected. Due to the high pressure being relieved, the incisions for fasciotomy often gap open. To allow for swelling and pressure to decrease, the surgeon can’t close them right away. Your surgeon may use skin grafts or other methods to close the wounds later, when it’s safe to do so.

Recovery and prognosis after fasciotomy depend on how much time passes before treatment. You should have an excellent recovery if a surgeon operates before permanent muscle damage occurs. But a delay in treatment can lead to muscle damage, and recovery and prognosis will depend on the degree of damage. This can range from mild damage with a good recovery, to severe damage that leads to disability. This emphasizes the importance of early diagnosis and treatment.

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Written by:

Steve Meadows, MD

Steve Meadows, MD, is a board-certified orthopedic surgeon with advanced fellowship training in hand and upper extremity surgery. He has been practicing orthopedic surgery for 30 years.

Edited by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined her interests in clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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