Inflammation: What You Need To Know (2024)

What is inflammation?

Inflammation is your body’s response to an illness, injury or something that doesn’t belong in your body (like germs or toxic chemicals). Inflammation is a normal and important process that allows your body to heal. Fever, for example, is how you know your body’s inflammatory system is working correctly when you’re ill. But inflammation can harm you if it occurs in healthy tissues or goes on for too long.

When an invader (like a virus) tries to enter your body, or you get injured, your immune system sends out its first responders. These are inflammatory cells and cytokines (substances that stimulate more inflammatory cells). These cells begin an inflammatory response to trap germs or toxins and start healing injured tissue. Inflammation can cause pain, swelling or discoloration. These are signs your body is healing itself. Normal inflammation should be mild, and pain shouldn’t be extreme.

But inflammation can also affect parts of your body you can’t see. Inflammatory responses that occur behind the scenes can help you heal, but other times, they can harm your health.

What’s the difference between acute and chronic inflammation?

There are two main types of inflammation: acute and chronic. Acute inflammation is sudden and temporary, while chronic inflammation can go on for months or years.

Acute inflammation

This is your immune system’s response to a sudden injury or illness. Inflammatory cells travel to the site of injury (like a cut on your finger) or infection and start the healing process.

Infections in different parts of your body can cause sudden, and usually short-lived, inflammation. For example, bacterial infections like strep throat and viral infections like the flu can cause throat inflammation. Other bacterial and viral infections can cause inflammation of your small intestine (enteritis).

Acute inflammation may last for a few hours to a few days, depending on your condition.

Chronic inflammation

This is when your body continues sending inflammatory cells even when there’s no danger. For example, in rheumatoid arthritis, inflammatory cells and substances attack joint tissues. This leads to inflammation that comes and goes and can cause severe damage to your joints.

With chronic inflammation, processes that normally protect your body end up hurting it. Chronic inflammation can last for months or years. You may have periods where it improves and other times when it gets worse.

Researchers have linked chronic inflammation to a wide range of conditions (inflammatory diseases).

What are the symptoms of acute inflammation?

When an injury to a specific part of your body occurs, you may notice:

• Discolored or flushed skin.
• Pain or tenderness that should be mild and only in the area of the injury.
• Swelling (for example, knee inflammation).
• Skin that feels hot to the touch.
• Inability to use that part of your body as you normally would (for example, reduced range of motion).

What are the symptoms of chronic inflammation?

Chronic inflammation symptoms may be harder to spot than acute inflammation symptoms. You may have:

• Abdominal (belly) pain.
• Chest pain.
• Fatigue and/or insomnia.
• Fever.
• Joint pain or stiffness.
• Mouth sores.
• A skin rash.
• Depression, anxiety and other mood disorders.
• Gastrointestinal (GI) issues, like diarrhea, constipation and acid reflux.
• Weight gain or weight loss.
• Frequent infections.

What conditions are associated with chronic inflammation?

Chronic inflammation is involved in the disease process of many conditions, including:

• Autoimmune diseases, like lupus, rheumatoid arthritis (RA), psoriasis and ankylosing spondylitis (AS).
• Cardiovascular diseases, such as heart disease and high blood pressure.
• Certain cancers.
• Gastrointestinal diseases, like Crohn’s disease and inflammatory bowel disease.
• Lung diseases, like asthma and chronic obstructive pulmonary disease (COPD).
• Mental health conditions, such as depression and anxiety.
• Metabolic diseases, like Type 2 diabetes.
• Neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease.

Together, inflammatory diseases account for more than half of all deaths globally.