Arthritis is common, especially among seniors. Here's what causes it.

Few medical conditions seem as inevitable when aging as does arthritis. It's an understandable assumption considering that the Centers for Disease Control and Prevention estimates that the disorder affects more than 58 million adults in the United States alone. "Arthritis is a very common condition that varies in severity and can affect people of all ages, but it is more prevalent in the elderly," says Dr. John Whyte, a practicing physician in Washington D.C. and the chief medical officer at WebMD.

At the same time, arthritis is considered a manageable condition for most individuals - though some people are more likely to develop it than others. Here's why, plus how to treat the disease if it arises.

What is arthritis? 

Arthritis is a disorder that's characterized by "inflammation and destruction in one or more joints, causing pain and stiffness and resulting in limited range of motion," says Whyte. Someone dealing with it will usually also experience swelling and tenderness in their joints. 

While many people speak of arthritis as if it was a singular disease, there are over 100 different types of arthritis, and osteoarthritis is, by far, the most common one. "About half of all Americans develop osteoarthritis in at least one joint in their lifetimes," says Dr. Ahmed Elghawy, a rheumatologist at Cleveland Clinic.

Whyte explains that osteoarthritis results from the wear and tear of the cartilage in joints, but the other most common type of arthritis - known as rheumatoid arthritis - is recognized "as an autoimmune disorder where the immune system mistakenly attacks the joints."

What causes arthritis? 

Because of the wear-and-tear nature of arthritis, some groups of people are more likely to develop different types of the condition than others. Individuals who are overweight or obese, for instance, "are more likely to get osteoarthritis due to the abnormal wear and tear on joint surfaces and the surrounding bone," explains Dr. Brent Lambson, a board-certified sports medicine physician at Revere Health Orthopedics in Utah.

Other people may get osteoarthritis or rheumatoid arthritis as a result of an infection or because of a current or past injury that disrupts the normal function of a joint. "Personal habits such as smoking can predispose an individual to rheumatoid arthritis," says Lambson. Gender can also affect multiple types of arthritis as women more commonly develop the disease than men. 

Those most at risk for developing arthritis, however, are the elderly, "due to the natural degeneration of joint cartilage over time," says Whyte.  This is usually due to extended use of joints throughout one's lifetime and because of cartilage degeneration that occurs naturally with age. 

People with autoimmune conditions may also be more likely to develop rheumatoid arthritis as "the immune system can target the joints, causing inflammation and resulting in pain, swelling, warmth, and stiffness," says Dr. Vivek Nagaraja, a rheumatologist at Mayo Clinic in Arizona

"Additionally, because arthritis is often heavily influenced by one’s anatomy, there also appears to be a genetic component to arthritis," says Elghawy. For instance, "we have found that if half of your family members develop arthritis in certain areas, then it is more likely to happen to you in that area."

How to treat arthritis

Regardless of what causes or contributes to arthritis across various groups of people, it can be helpful to know what to look out for. "If you experience pain, swelling, stiffness or increased warmth or redness over your joints, it is time to seek help from your primary care provider," advises Nagaraja. One's doctor can properly diagnose the type of arthritis and recommend a proper management plan. Diagnosis usually requires "x-rays or other imaging as well as blood tests," says Whyte. 

Once diagnosed, the first line of treatment is often related to lifestyle modifications which may include "quitting smoking, managing your weight, getting regular exercise, and practicing proper body mechanics," says Nagaraja.

From there, treatment options vary based on the type of arthritis one has but can range across different forms of physical therapy, bracing, surgery, or medications such as anti-inflammatories or steroids, antiviral medication, or disease-modifying medications. 

With proper medical attention and self-care, says Elghawy, "those with arthritis are often able to still complete their regular activities of daily living."