Tendinitis
Tendinitis is inflammation or irritation of a tendon, any one of the thick fibrous cords that attach muscles to bones. The condition, which causes pain and tenderness just outside a joint, can occur in any of your body's tendons. Tendinitis is common around your shoulders, elbows, wrists and heels.

If tendinitis is severe and leads to the rupture of a tendon, you may need surgical repair. But many times, rest and medications to reduce the pain and inflammation of tendinitis may be the only treatments you need. You can take preventive measures to reduce your chance of developing tendinitis.

Symptoms
Symptoms of tendinitis that are produced near a joint aggravated by movement include the following:

• Pain
• Tenderness
• Mild swelling, in some cases

Tendinitis in various locations in your body produces these specific types of pain:

• Tennis elbow - This type causes pain on the outer side of your forearm near your elbow when you rotate your forearm or grip an object. Golfer's elbow causes pain on the inner part of your elbow.
• Achilles tendinitis - This form causes pain just above your heel.
• Adductor tendinitis - This type leads to pain in your groin.
• Patellar tendinitis - In this type, you experience pain just below your kneecap.
• Rotator cuff tendinitis - This tendinitis leads to shoulder pain.

If the sheath of tissue that surrounds the tendon becomes scarred and narrowed in small joints, such as the finger, it may cause the tendon to lock in one position, such as occurs in the condition called trigger finger. The pain of tendinitis is usually worse with activities that use the muscle that is attached to the involved tendon.

Causes
Tendons are usually surrounded by a sheath of tissue similar to the lining of the joints (synovium). They're subject to the wear and tear of aging, direct injury and inflammatory diseases. The most common cause of tendinitis is injury or overuse during work or play.

The pain is usually the result of a small tear in or inflammation of the tendon that links your muscle to your bone. Tendinitis can be associated with inflammatory diseases that occur throughout your body, such as rheumatoid arthritis.

Risk factors
The risk is greater of developing tendinitis if you perform excessive repetitive motions of your arms or legs.

For instance, professional baseball players, swimmers, tennis players and golfers are susceptible to tendinitis in their shoulders, arms and elbows. Basketball players, runners and dancers are more prone to tendon inflammation in their legs and feet.

But you don't have to be a professional athlete to develop tendinitis. The incidence of tendinitis increases with age as muscles and tendons lose some of their elasticity. Improper technique in any sport is one of the primary causes of overload on tissues, including tendons, which can contribute to tendinitis.

Some common names for various tendinitis problems are tennis elbow, golfer's elbow, pitcher's shoulder, swimmer's shoulder and jumper's knee.
 
Prevention
To reduce your chance of developing tendinitis, follow these suggestions:

• Ease up - Avoid activities that place excessive stress on your tendons, especially for prolonged periods. If you notice pain during a particular exercise, stop and rest.
• Mix it up - If one exercise or activity causes you a particular, persistent pain, try something else. Cross-training can help you mix up an impact-loading exercise, such as running, with lower impact exercise, such as biking or swimming.
• Improve your technique - If your technique in an activity or exercise is flawed, you could be setting yourself up for problems with your tendons. Consider taking lessons or getting professional instructions when starting a new sport or using exercise equipment.
• Stretch - After warming up and again after you exercise, take time to stretch in order to maximize the range of motion of your joints. This can help to minimize repetitive microtrauma on tight tissues.
• Use proper workplace ergonomics - At your workplace, get a proper ergonomic assessment. Fitting your work space to your body is essential to ensure that no tendons are continually stressed or overloaded. 
• Prepare your muscles to play - Strengthening muscles used in your activity or sport can help them better withstand stress and load.

To avoid a recurrence of tendinitis, warm up before exercising and cool down afterward. Strengthening exercises may help prevent further episodes of tendinitis.