What Is Subacromial Bursitis?

Written by Hirania Luzardo
Medically Reviewed by Poonam Sachdev on July 07, 2025
6 min read

Subacromial bursitis is a painful condition that affects your shoulder, causing pain and swelling. It affects the bursa, a small sac filled with fluid that helps lessen friction between the bones, muscles, and tendons. The subacromial bursa sits just below the top bone of your shoulder, called the acromion. It can become irritated due to overuse, injury, or repetitive motion. This can cause sharp or aching pain.

You have small sacs all over your body called  bursae, which is the plural of bursa. These sacs help your joints move smoothly. When a bursa gets inflamed, it swells and fills with too much fluid. That’s what causes bursitis. The subacromial bursa in your shoulder helps the rotator cuff muscles and tendons work easily and without friction. 

You find bursae in many parts of your body, including:

  • Shoulders
  • Elbows
  • Hips
  • Knees
  • Heels
  • The base of your big toe, where pressure and movement are frequent
  • Other joints that do repetitive movement, such as the wrists, ankles, or even some areas of your spine

Subacromial bursitis can happen when something irritates or puts pressure on the bursa in your shoulder.  Sports injuries, weak muscles, poor posture, joint problems, and certain health conditions can cause it. These include:

Repeated movements. Activities such as lifting, reaching, or throwing over and over can strain your shoulder.

Weak shoulder muscles. A weak rotator cuff can cause your shoulder to move out of balance and press on the bursa.

Tight space in your shoulder. A narrow gap between your shoulder bones can pinch the bursa during movement.

Health conditions. Conditions such as arthritis, gout, tendonitis, thyroid disease, or diabetes can lead to swelling, slow healing, or extra pressure around the bursa.

Infection. Bacteria can enter your bursa through a cut, an injection, or an infection somewhere else in your body. This might cause painful swelling. The most common cause is Staphylococcus aureus.

Your age. Bursitis in your shoulder becomes more common with age.

The most common symptoms of subacromial bursitis in your shoulder include:

  • Pain in your shoulder
  • Swelling around the joint
  • Stiffness that limits your movement
  • Less range of movement without pain
  • Tenderness from even a light touch
  • Red or discolored skin over the shoulder
  • Heat or warmth in the area

If your bursitis worsens, you may not be able to move your shoulder without pain. This can lead to a condition called frozen shoulder, also known as adhesive capsulitis. In this condition, your shoulder becomes very stiff and painful, especially in the first few months.

Your doctor will begin by asking about your symptoms. They'll check to see if your shoulder feels warm or sore. They’ll also gently move your arm in different directions to check your shoulder movement.

Your doctor may use several tests to find out if you have subacromial bursitis:

X-ray. This helps check for other causes of your shoulder pain.

MRI. This helps find damage in the soft tissues.

Ultrasound. This shows if your bursa is swollen.

Aspiration. This helps check for infection or gout, which can cause subacromial bursitis. Your doctor may use a thin needle to take fluid from your bursa.

Blood tests. These tests help your doctor rule out other health problems or an infection that could cause subacromial bursitis.

Anesthetic injection. Your doctor could give you a shot near your bursa to numb the painful area. If this eases your pain, it helps confirm subacromial bursitis as the cause.

Subacromial bursitis might get better if you allow your shoulder time to rest. Your treatment plan depends on how much pain you have and what caused the problem.

You may use one or more of the following options to get rid of symptoms and support healing:

Rest. You'll need to take a break from all activities or movements that cause you pain.

Over-the-counter pain relief. Medicines such as aspirin , ibuprofen, or naproxen can ease swelling and soreness.

Ice. A cold pack on your shoulder will reduce swelling. Aim for 10-15 minutes once or twice a day.

Medicine. If your pain is intense, your doctor may inject a steroid into the area around your shoulder bursa. This will help manage your pain. If an infection turns out to be the cause of your bursitis, you may need antibiotics.

Stretching and strengthening your shoulder. Once your pain goes away, your doctor might give you exercises to do to help your shoulder return to its normal range of motion. They may also suggest physical therapy.

If rest, medicine, and therapy don't help your shoulder feel better, your doctor might talk to you about surgery. Most of the time, surgery is done with shoulder arthroscopy. This is a procedure that uses small tools and a camera to look inside your joint.

During surgery, your doctor might remove swollen tissue, bone spurs, or the inflamed bursa to make more space in your shoulder. Your body can naturally grow a new cushion in the same spot over time, especially if the original bursa was too damaged to heal.

You might lower your chances of subacromial bursitis if you:

  • Stretch your shoulders before any activity. This helps prepare your joints and muscles.
  • Do shoulder exercises that match your sport, job, or hobby. These exercises build strength and support your shoulder.
  • Take breaks during hard work or training. Short rests protect your shoulder from overuse.
  • Stop the activity if your shoulder starts to hurt. Pushing through pain can worsen the problem.

You may not always prevent subacromial bursitis. A sudden injury can cause bursitis without warning. Some infections can also spread to the bursa without symptoms at first. If your doctor gives you antibiotics, take the full dose exactly as prescribed. This helps remove the infection and keeps it from spreading deeper into your shoulder joint.

Subacromial bursitis can cause pain in your shoulder, but treatment can help. Rest, ice, and medicine often ease swelling and discomfort. Your doctor might also suggest physical therapy or a steroid shot to ease pain. In some cases, you might need surgery to make more space in your shoulder. With the right care, you can recover and get back to your daily activities.

How long does subacromial bursitis take to heal?

Subacromial bursitis usually heals in a few weeks if you rest, ice your shoulder, and follow your treatment plan. If your pain lasts longer or you have a more serious case, it might take a few months to fully recover. Starting treatment early helps you heal faster and avoid long-term problems.

Can an MRI show subacromial bursitis?

An MRI shows subacromial bursitis when your bursa looks swollen or filled with extra fluid. Your doctor checks the scan for thick tissue or fluid buildup under the top bone in your shoulder. The MRI also helps find other problems, such as tendon tears or joint damage.

Does shoulder bursitis ever go away?

Subacromial bursitis often goes away with rest, ice, and other simple treatments. Many people start to feel better in a few weeks. Your doctor might also suggest medicine, physical therapy, or a steroid shot. These treatments help you heal faster and keep the pain from coming back.

Is subacromial bursitis serious?

It can become serious if not treated properly. It might start with mild pain and stiffness, but those symptoms can worsen over time and limit your shoulder movement. In rare cases, the bursa might get infected and cause fever, redness, and swelling that spreads. You should seek medical care immediately if this happens.

How can I test for subacromial bursitis?

To test for subacromial bursitis, your doctor asks about your symptoms and checks how well you can move your shoulder. They might order an X-ray to rule out bone problems or use an ultrasound or MRI to look for swelling in the bursa. If needed, your doctor can also use a needle to take fluid from your shoulder and check for infection. In some cases, a blood test helps find other health issues that could affect your shoulder.