What is inflammation?

Inflammation is the body’s natural protective response to injury, infection or harmful stimuli such as pathogens, damaged cells or irritants.

The purpose of inflammation is to eliminate the cause of harm, remove damaged tissue and start the healing process.

Inflammation can either be acute, meaning short-term, or chronic, meaning long-term.

Acute inflammation is a rapid, short-term immune response to injury or infection. It aims to eliminate the cause and initiate tissue repair.
Chronic inflammation is a prolonged, persistent inflammatory response. It occurs when the cause is not eliminated. Chronic inflammation often leads to ongoing tissue damage and repair at the same time.

Inflammation harms both healthy and diseased tissue by design, not by mistake. This broad response helps your body quickly eliminate microbial pathogens that pose an immediate threat to survival. However, long-term inflammation is linked to diseases, including cancer.

What are the signs of inflammation?

Inflammation doesn’t only impact tissues. The body’s immune signals also act on the nervous system and brain. So, how can you tell if your body is inflamed?

In general, you might feel:

Pained
Stiff
Tired
Foggy
Unwell

The signs of inflammation also depend on whether the inflammation is acute or chronic.

Signs of acute inflammation

The classic physical signs of acute inflammation include:

Redness
Swelling
Heat
Pain
Loss of function in the affected area

For example, imagine you sprain your ankle. Your ankle might feel warm, puffy, tender and harder to use as your body sends blood and immune cells to fight the injury.

Signs of chronic inflammation

Physical signs of chronic inflammation are often subtle and develop gradually. They can include:

Persistent fatigue
Joint pain or stiffness
Digestive issues, including bloating, diarrhea and constipation
Skin problems, including rashes, eczema and psoriasis
Headaches
Mood changes, including anxiety, depression and brain fog

Is inflammation in the body linked to any health concerns?

Yes, chronic inflammation is linked to several health concerns, including:

Cardiovascular disease. Inflammation contributes to the hardening of arteries, or atherosclerosis. This increases the risk of heart attacks and stroke.
Type 2 diabetes and obesity-related metabolic dysfunction.
Autoimmune disorders such as rheumatoid arthritis, inflammatory bowel disease such as Crohn’s disease and ulcerative colitis, psoriasis and multiple sclerosis are driven by inappropriate chronic inflammatory responses.
Alzheimer’s disease and other neurodegenerative disorders.
Cancer. Research shows that chronic inflammation contributes to the initiation, progression and spread of cancers, including colorectal, lung, stomach, esophageal, breast and liver. Ongoing inflammation can damage DNA, promote cell proliferation and create an environment that favors tumor growth.

But it’s important to remember that inflammation is simply a risk factor, not a guarantee that you’ll develop any sort of disease or cancer. Many factors, including genetics and lifestyle, also play a role in inflammation and disease risk.

How can we reduce inflammation in the body?

Your lifestyle choices can reduce inflammation and lower your risk of inflammation-related health conditions. Here are nine examples of healthy habits that can reduce inflammation.

Eat a healthy diet

Diet is an important modifiable factor that influences inflammatory processes and may affect cancer risk.

While some food groups can reduce inflammation, others can increase it. These include trans fats, saturated fats, omega-6 fats, refined carbohydrates, foods with excess sugar, alcohol, red and processed meats, and too much of any macronutrient.

Eating inflammatory foods often over time can contribute to chronic inflammation. Pro-inflammatory diets are linked to higher risks of cancers, including esophageal, oral, pharynx, breast, lung, colorectal and stomach cancer.

RELATED: Examples of foods that increase and reduce inflammation

The good news? A healthy diet can help reduce inflammation. UT MD Anderson dietitians recommend eating meals rich in whole grains, vegetables, fruits, beans, nuts and seeds. Focus on eating more complex carbohydrates, fiber, lean protein and n-3 polyunsaturated fatty acids and less saturated fats and refined sugars.

While eating healthy doesn’t have to mean following a specific diet, the DASH (Dietary Approaches to Stop Hypertension) diet and Mediterranean diet both include lots of plant-based foods, fiber and antioxidants, which help reduce inflammation and oxidative stress.

To determine foods that contain antioxidants, let your eyes be your guide. When a plant is naturally vibrant and deeply colored, it indicates the presence of antioxidants and beneficial phytonutrients, or plant compounds.

Stay hydrated

While focusing on a healthy diet, make sure you drink enough fluid. Dehydration can put stress on the body.

Of course, not all beverages impact your body the same way. For example, alcohol and sugary drinks like soda can contribute to inflammation. A healthy go-to? Regular water.

Manage underlying health issues

There are many disease states that cause or worsen inflammation. For example, many cancer patients have inflammation. Additionally, flares of certain diseases, such as inflammatory bowel disease, increase inflammation in the body.

To manage inflammation caused by health issues, work with your care team to treat the underlying issue.

Practice stress management

One surprising factor that influences inflammation? Stress. This is because certain stress hormones play a part in inflammation. To manage your stress levels, our experts recommend seeking emotional support, trying relaxation techniques and following healthy lifestyle habits.

Get enough sleep

Ever noticed how you feel a bit worse when you aren’t sleeping well? This may be due to a weakened immune system. UT MD Anderson doctors recommend adults get seven to nine hours of sleep each night.

Decrease exposure to environmental risk factors

Environmental risk factors, including exposure to pollution, chemicals and toxins, can increase inflammation. For example, lab studies have found that microplastics that build up in the body can cause inflammation.

While it can feel challenging to avoid all environmental risk factors, focus on small everyday actions. Maybe that means choosing glass instead of plastic food storage, considering the ingredients in your personal care products or tracking air quality.

Practice skin safety

Daily habits like wearing sunscreen can protect your skin from sunburn, a type of inflammation. UT MD Anderson dermatologists recommend choosing a sunscreen that is at least sun protection factor (SPF) 30 and broad-spectrum. Choose a water-resistant option if you will be in the water or sweating. Be sure to reapply every two hours or after swimming or sweating. Reapply even more frequently if you are using spray sunscreen.

In addition to wearing sunscreen, protect your skin by:

Avoiding tanning beds
Seeking shade from 10 a.m. to 4 p.m., when sun rays are the strongest
Choosing protective clothing and sunglasses

Get physical activity

Physical activity has many health benefits that help reduce your risk for cancer and other diseases: it helps you maintain a healthy body weight, plays a role in hormone regulation and supports digestion.

UT MD Anderson recommends aiming for at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise each week.