Bursitis happens when a bursa becomes irritated and swells. The most common causes of bursitis are overuse and putting too much pressure on a bursa. The pain from an inflamed bursa may develop suddenly or build up over time.
Bursitis is painful, and it can be frustrating to learn your job or hobby you love caused an injury inside your body. The good news is that bursitis is usually preventable. The first step is figuring out which movements caused the irritation.
Bursae are small fluid-filled sacs that reduce friction between moving parts in your body's joints. Hip bursitis is inflammation or irritation of one or more of the bursae (shown in blue) in your hip.
Bursae are small fluid-filled sacs (shown in blue) that reduce friction between moving parts in your body's joints. Knee bursitis is inflammation or irritation of one or more of the bursae in your knee.
The most common locations for bursitis are in the shoulder, elbow and hip. But you can also have bursitis by your knee, heel and the base of your big toe. Bursitis often occurs near joints that perform frequent repetitive motion.
Treatment typically involves resting the affected joint and protecting it from further trauma. In most cases, bursitis pain goes away within a few weeks with proper treatment, but recurrent flare-ups of bursitis are common.
Bursitis is inflammation of the bursa. There are two major bursae in the hip that typically become irritated and inflamed. One bursa covers the bony point of the hip bone called the greater trochanter. Inflammation of this bursa is called trochanteric bursitis.
The main symptom of trochanteric bursitis is pain at the point of the hip. The pain usually extends to the outside of the thigh area. In the early stages, the pain is usually described as sharp and intense. Later, the pain may become more of an ache and spread across a larger area of the hip.
To diagnose hip bursitis, the doctor will perform a comprehensive physical examination, looking for tenderness in the area of the point of the hip. They may also perform additional tests to rule out other possible injuries or conditions. These tests can include imaging studies, such as X-rays, bone scanning, and magnetic resonance imaging (MRI) scans.
Surgery is rarely needed for hip bursitis. If the bursa remains inflamed and painful after you have tried all nonsurgical treatments, your doctor may recommend surgical removal of the bursa. Removal of the bursa does not hurt the hip, and the hip can function normally without it.
Posterior Achilles tendon bursitis. This type of bursitis, also called Haglund deformity, is in the bursa located between the skin of the heel and the Achilles tendon. This attaches the calf muscles to the heel. It is aggravated by a type of walking that presses the soft heel tissue into the hard back support of a shoe.
Hip bursitis. Also called trochanteric bursitis, hip bursitis is often the result of injury, overuse, spinal abnormalities, arthritis, or surgery. This type of bursitis is more common in women and middle-aged and older people.
Elbow bursitis. Elbow bursitis is caused by the inflammation of the bursa located between the skin and bones of the elbow (the olecranon bursa). Elbow bursitis can be caused by injury or constant pressure on the elbow (for example, when leaning on a hard surface).
Knee bursitis. Bursitis in the knee is also called goosefoot bursitis or Pes Anserine bursitis. The Pes Anserine bursa is located between the shin bone and the three tendons of the hamstring muscles, on the inside of the knee. This type of bursitis may be caused by lack of stretching before exercise, tight hamstring muscles, being overweight, arthritis, or out-turning of the knee or lower leg.
A bursa is a small, fluid-filled sac that acts as a cushion between a bone and other moving parts, such as muscles, tendons, or skin. Bursitis occurs when a bursa becomes inflamed. People get bursitis by overusing a joint. It can also be caused by an injury. It usually occurs at the knee or elbow. Kneeling or leaning your elbows on a hard surface for a long time can make bursitis start. Doing the same kinds of movements every day or putting stress on joints increases your risk.
Symptoms of bursitis include pain and swelling. Your doctor will diagnose bursitis with a physical exam and tests such as x-rays and MRIs. He or she may also take fluid from the swollen area to be sure the problem isn't an infection.
Treatment of bursitis includes rest, pain medicines, or ice. If there is no improvement, your doctor may inject a drug into the area around the swollen bursa. If the joint still does not improve after 6 to 12 months, you may need surgery to repair damage and relieve pressure on the bursa.
Routine laboratory blood work is generally not helpful in the diagnosis of noninfectious bursitis but is appropriate when septic bursitis or underlying autoimmune disease is suspected. Aspiration and analysis of bursal fluid should be done to rule out infectious or rheumatic causes and may also be therapeutic.
MRI is usually unnecessary but if needed is very sensitive for identification of bursitis, and can rule out suspected solid tumors and define pathology for possible surgical excision. Ultrasonography is useful for further imaging of the bursa when the diagnosis is uncertain, and can guide diagnostic aspiration or therapeutic injections.
Patients with suspected septic bursitis should be treated with antibiotics while awaiting culture results. Surgical excision of bursae may be required as a last resort for chronic or frequently recurrent bursitis.
All of the approximately 160 bursae in the human body are potentially susceptible to injury. The three upper-extremity bursae that are most commonly affected by bursitis are the subacromial, subscapular, and olecranon bursae. 
In the knee, bursae commonly affected by bursitis include the medial collateral ligament bursa, the anserine (pes anserinus) bursa (see the image below), the prepatellar bursa (located anteriorly over the patella, between patella and skin), the infrapatellar bursa (containing a superficial component lying between the patellar ligament and the skin and a deep component lying between the patellar ligament and the proximal anterior tibia), and the popliteal bursae, or Baker cysts (located in the posterior joint capsule of the knee). 
In the ankle, two bursae are found at the level of insertion of the Achilles tendon. The superficial one is located between the skin and the tendon, and the deep one is located between the calcaneus and the tendon. The latter is the one more commonly affected by bursitis.
There are three phases of bursitis: acute, recurrent, and chronic.  During the acute phase of bursitis, local inflammation occurs and the synovial fluid is thickened, and movement becomes painful as a result. Chronic bursitis leads to continual pain and can cause weakening of overlying ligaments and tendons and, ultimately, rupture of the tendons. Because of the possible adverse effects of chronic bursitis on overlying structures, bursitis and tendinitis may occur together; the differential diagnosis should include both of these diagnoses.
The subacromial bursa facilitates movement of the supraspinatus tendon and becomes inflamed secondary to repetitive overuse injury of this tendon. Subacromial bursitis is often coexistent with supraspinatus tendinitis and partial- or complete-thickness tears of the supraspinatus tendon (1 of the 4 tendons comprising the rotator cuff). 
The more superficial of the 2 olecranon bursae commonly involved in bursitis is predisposed to direct trauma or cumulative microtrauma from activities requiring frequent elbow motion (eg, swimming, skiing, gymnastics, and weightlifting). This type of bursitis is often recurrent. [11, 12, 13]
Iliopsoas bursitis arises when a defect develops in the anterior part of the hip joint capsule, allowing communication of the joint with the bursa. It is often associated with hip pathology (eg, rheumatoid arthritis or osteoarthritis) or recreational injury (eg, running). Infection of the iliopsoas bursa is rare.
Greater trochanter bursitis is common in overweight middle-aged women and is associated with acute trauma, overuse, and mechanical factors. The clinical presentation is of deep, aching lateral hip pain that may radiate into the buttocks or lateral knee. Pain is worse with activity and stretching and may be worse at night, especially when the patient lies on the affected side. Palpation over the greater trochanter elicits severe tenderness. Physical examination reveals pain with resisted hip abduction and external rotation. [14, 15, 16, 17]
Anserine (pes anserinus) bursitis is not usually associated with overuse but may occur in patients with medial compartmental osteoarthritis. Clinically, patients complain of pain and tenderness over the anteromedial knee that is worse with knee flexion. This condition may be confused with medial meniscal pathology. [18, 19]
Popliteal bursae (Baker cysts) are associated with local swelling and pain on walking, jumping, and squatting. Magnetic resonance imaging (MRI) or ultrasonography can differentiate an isolated bursitis from intra-articular injury. (See also Baker Cyst.)
Bursitis has many causes, including autoimmune disorders, crystal deposition (gout and pseudogout), infectious diseases, traumatic events, and hemorrhagic disorders, as well as being secondary to overuse. Repetitive injury within the bursa results in local vasodilatation and increased vascular permeability, which stimulate the inflammatory cascade. Subdeltoid and subacromial bursitis have been reported after vaccination, when poor technique results in direct injection of the vaccine into the bursa. 
Septic (infectious) bursitis is most common in superficial bursae. In the majority (50-70%) of cases, it results from direct introduction of microorganisms through traumatic injury or through contiguous spread from cel