What Is Tendonitis and How Long Does It Last?

Tendonitis (also spelled tendinitis) is inflammation of a tendon resulting in pain, swelling, and the loss of joint function. It is most often caused by repetitive motion injuries but may also be due to an infection or inflammatory disease. The treatment may involve rest, ice application, over-the-counter painkillers, and steroid injections.

This article explains what tendons are, including the causes and symptoms of tendonitis. It also describes how tendonitis is treated and ways to prevent it.

What Are Tendons?

Tendons are tough bands of fibrous connective tissues that attach bones to muscles. Like ligaments (which connect bones to other bones), tendons are composed mainly of collagen.

There are over 400 tendons in the human body. Four of the most prominent—and the ones most vulnerable to injury—include:

• Quadriceps tendons, including the patellar tendon, which help bend and straighten the knees
• Rotator cuff tendons which enable rotation and movement of the shoulders
• Biceps tendons which help bend the elbows and rotate the forearms
• Achilles tendons which help move your foot up and down or side to side

Causes of Tendonitis

The most common cause of tendonitis is a repetitive stress injury caused by the overuse of a tendon. These injuries are common with occupations involving manual labor or with athletes or musicians who use certain joints and muscles repetitively.

Examples of repetitive stress tendon injuries include:

• Tennis elbow (lateral epicondylitis)
• Jumper's knee (patellar tendonitis)
• Rotator cuff tendinopathy
• Achilles tendonitis
  

Less commonly, tendonitis can be caused by conditions like:

• Infections (including infectious tendosynovitis)
• Osteoarthritis (caused by stress placed on tendons by damaged joints)
• Gout (caused by deposits of uric acid crystals in joints)
• Diabetes (caused by whole-body inflammation spurred by high blood sugar)

Symptoms of Tendonitis

Tendonitis is characterized by inflammation, the body's natural response to injury, infection, or disease. Symptoms range from mild to severe and can either be acute (sudden) or chronic (persistent), depending on the underlying cause.

Symptoms of tendonitis include:

• Pain, worsening with exercise or specific movements
• Tenderness to the touch
• Swelling
• Loss of joint function

If severe or left untreated, tendonitis can worsen, causing a partial tear in the tendon or, in extreme cases, a complete rupture.

How Long Does Tendonitis Last?

With proper treatment, acute tendonitis caused by overuse will usually resolve within three months, although complete recovery can take up to six months before you can return to sports.

Even so, recurrence is common unless changes are made to how you use a joint. If changes are not made, an acute injury like tennis elbow will become chronic and may even lead to a tendon rupture.

Chronic tendonitis may require ongoing care to manage symptoms and prevent exacerbations (flare-ups). This includes treating or managing the underlying condition like gout or diabetes.

At-Home Treatment

The treatment of tendonitis is usually conservative. The first step is to treat the acute pain followed by a recovery program to regain joint function and prevent future injury.

Tendonitis is commonly treated at home with:

• Rest, including elevation of the injured joint to reduce swelling and pain
• Ice application to ease acute pain and swelling
• Compression bandages, braces, or crutches to support and protect the injured joint
• Nonsteroidal anti-inflammatory drugs (NSAIDs) like Advil (ibuprofen) and Aleve (naproxen) available over the counter

Once the acute swelling and pain have eased, you will need to gradually incorporate exercises to rebuild strength and regain the range of motion of the injured joint.

These may include:

• Isometric elbow exercises
• Elbow range of motion exercises
• Rotator cuff resistance band exercises
• Rotator cuff strengthening exercises
• Knee physical therapy
• Achilles tendonitis exercises

Other Types of Tendon Injuries

Tendonitis is one condition affecting tendons. When tendonitis is chronic, it is commonly referred to as tendinosis. The degeneration of the tendons due to inflammatory or non-inflammatory conditions is referred to as tendinopathy.

Tendinosis

While the terms "tendonitis" and "tendinosis" are sometimes used interchangeably, there are subtle but striking differences. At its heart, tendinosis is accumulated trauma to a tendon. It may be caused by inflammation but it doesn't necessarily involve inflammation.

Tendinosis can occur when overuse continues without giving the tendon time to heal. When this happens, even tiny movements, such as clicking a mouse or lifting your arm, can cause chronic tenderness and pain.

Tendinosis is also characterized by the loss of collagen which can increase the risk of re-injury or rupture.

The distinction between tendonitis and tendinosis is important insofar as the goals and duration of treatment can differ. Tendinosis may require chronic, ongoing management with the aim of preserving rather than restoring joint function.

Tendinopathy

Tendinopathy encompasses a wide range of conditions affecting tendons, both inflammatory and non-inflammatory. As with tendinosis, "tendinopathy" and "tendonitis" are often used interchangeably. However, tendinopathy doesn't describe inflammation as much as it does the process of tendon deterioration.

This not only includes deterioration of a tendon by repetitive stress, infection, or disease but also the degeneration of the tendon by things like:

• Reduction of blood flow to tendons due to aging or vascular disease
• Medications that cause tendon damage, such as high-dose corticosteroids
  
• Hypothyroidism (low thyroid function) which can decrease collagen production

As such, tendinitis and tendinosis are subcategories that fall under the umbrella of tendinopathy.

Preventing Tendon Injuries

If you can determine the cause of the tendon injury and make a correction, you can often avoid long-term problems.

If your pain is from overuse, reduce or stop that activity and find a substitute activity. If the pain is from poor technique or poor ergonomics, consult a coach or trainer for skills training. If you can eliminate the offending factors, you have a much greater likelihood of a full recovery.

To prevent the return of tendon overuse injuries, athletes should maintain a training schedule that includes varied intensity and duration as well as the type of activity.

Summary

Tendonitis describes tendon inflammation that causes pain, swelling, and loss of joint mobility. It is usually caused by repetitive stress but can also occur due to inflammation caused by conditions like arthritis, diabetes, infection, or gout. Treatment is typically conservative, involving rest, ice application, compression, and OTC painkillers. A physical therapy program can prevent re-injury.