Comorbidities and Complications

Reviewed by: HU Medical Review Board

Many conditions tend to occur with rheumatoid arthritis (RA). Doctors use the term comorbidity to describe a condition that occurs at the same time as another condition.

Comorbid illnesses can interact in ways that make both worse. Morbidity should not be confused with mortality. Morbidity means disease or illness. Mortality means death.

Short-term inflammation is a good thing. You may recognize this type of inflammation with visible symptoms, such as redness, swelling, bruising, and pain. Short-term inflammation allows your immune system to repair itself from injury or disease.1

But too much inflammation can lead to problems. Long-term (chronic) inflammation is the driving force behind many chronic diseases. Your body is on high alert at all times, which makes healing more difficult.1

Cholesterol problems

High-density lipoprotein (HDL) is also known as “good cholesterol.” This is because it acts to “flush away” artery-clogging cholesterol (low-density lipoprotein, or LDL). In RA, high HDL cholesterol levels do not produce the heart protection usually seen in people without RA. Inflammation from RA changes the structure and job of HDL. Cholesterol problems may contribute to heart disease.2

The use of anti-inflammatory drugs, such as disease-modifying anti-rheumatic drugs (DMARDs), may also help improve cholesterol values in those with RA. More studies are needed to learn the risks and benefits of this.2

Heart and vessel problems

Chronic inflammation alone may lead to heart and vessel problems. Other risk factors add to the risk of heart and vessel problems, including:3

  • High blood pressure
  • Obesity
  • Inactivity
  • Smoking

Heart disease

When inflammation occurs in the blood vessels, a buildup of dangerous fatty plaque can occur. This buildup (atherosclerosis) can narrow or block blood vessels, causing heart and blood vessel problems. The buildup leads to heart and blood vessel disease, also known as cardiovascular disease or heart disease. Heart disease can cause heart attack and stroke.1,4,5

People with RA have a 50 to 70 percent increased risk for heart disease than those without RA.6


A stroke occurs when the blood supply to the brain is slowed or stopped. Compared to those without RA, those with rheumatoid arthritis have nearly double the risk for stroke. Inflammation may be the key factor that promotes this vessel damage. However, the other risk factors of heart disease are major factors as well.7,8

Other heart problems
Inflammation from RA increases the risk for developing other heart problems, including:8

  • Heart attack
  • Heart failure
  • High blood pressure


Some studies have shown that the risk for developing type 2 diabetes can increase more than 50 percent if you have RA. Studies have had mixed results, but there appears to be a link between RA and type 2 diabetes.9

This link may be because both RA and diabetes share similar risk factors. This includes factors like inflammation, obesity, and inactivity.9


Those with RA face an increased risk for infections. Infections mainly affect the joints and bones but may also affect other organs. The cause behind the increased risk for infection among those with RA is unclear. There are several factors that may contribute to this increased risk, including:10

  • Immune system malfunction common to RA
  • Drugs that suppress the immune system used to treat RA

There are other conditions or diseases that may occur alongside RA. Regular follow-up care with your doctors will help keep you healthy. Begin or continue a healthy lifestyle to avoid and prevent conditions that may occur with RA.


People with RA are at an increased risk of lung and lymphoma cancers compared with the general population. Incidence and death rates due to leukemia or lymphoma are about 2 times higher in those with RA than for those without RA.

Drugs used to treat RA may contribute to this risk. However, the rate of lymphoma increases as active RA persists and corresponds with the severity of disease. This makes proper treatment important.11,12

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