Common Causes of Inflammation and How to Reduce It (2024)

Inflammation is your body's defense against injury and infection. The five cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. However, some people with inflammation do not have any symptoms.

This article describes two types of inflammation—acute and chronic—and details the five signs. It also discusses other signs and complications of inflammation and treatment for acute and chronic inflammation.

Types of Inflammation

Inflammation can either happen in the short term (acute) or be a long-term response (chronic).

Acute Inflammation

Acute inflammation is a healthy and necessary function that helps the body attack bacteria and other foreign substances in the body. Once the body has healed, the inflammation gets better.

Acute inflammation can cause heat or warmth in the affected area.For example, an injured part of your body might feel warm to the touch.Sometimes, the heat is caused by a fever.

A few examples of common conditions that can cause acute inflammation include:

• Acute bronchitis (inflammation of the airways that carry air to the lungs)
• An infected body part (e.g., ingrown toenail)
• A sore throat related to the flu or another viral infection
• Dermatitis(which includes skin conditions like contact dermatitis, such as from poison ivy or nickel)
• Physical trauma
• Sinusitis (which can cause short-term inflammation in the membranes of the nose and surrounding sinuses, usually from a viral infection)
• Skin cuts and scratches

Chronic Inflammation

Chronic inflammation may continue to attack healthy areas if it doesn't "turn off." It may not be as visible as acute inflammation.

A few examples of chronic inflammatory conditions include:

• Inflammatory arthritis (a group of conditions distinguished by inflammation of joints and tissues (includingrheumatoid arthritis,lupus, andpsoriatic arthritis)
• Asthma (which causes inflammation in the air passages that carry oxygen to the lungs. Inflammation causes these airways to become narrow and breathing to become difficult)
• Periodontitis (which causes inflammation of gums and other supporting teeth structures. It is caused by bacteria triggered by local inflammation)
• Inflammatory boweldisease(IBD) (likeCrohn’s diseaseandulcerative colitis, which cause signs of inflammation in the GI tract)
• Eczema(chronic skin inflammation that causes red, itchy inflamed rashes in areas where the skin flexes, such as inside the elbows and behind the knees)
  

The 5 Signs of Inflammation

The five cardinal signs of inflammation can affect different parts of the body. Some signs overlap between body systems.

Pain

With both acute and chronic inflammation, inflammatory chemicals can stimulate nerve endings, causing the affected areas to feel more sensitive.

Inflammation can causepain in jointsand muscles.When inflammation is chronic, a person will have high levels of pain sensitivity and stiffness.The inflamed areas may be sensitive to touch.

Heat

When inflamed areas of the body feel warm, it is because there is more blood flow going to them.

People with arthritic conditions may have inflamed joints that feel warm to the touch.However, the skin around the joints may not have the same warmth.Whole-body inflammation may cause fevers due to the inflammatory response in the body when it is fighting off an infection or illness.

Redness

Inflamed areas of the body may look red because the blood vessels of inflamed areas are wider than usual.

Swelling

Swelling (edema) is common when a part of the body is inflamed.It is caused by fluid building up in tissues either throughout the body or in the affected area. Swelling can cause pressure on the skin and other tissue, leading to pain.

Swelling can also occur without inflammation, especially with injuries.

Loss of Function

Inflammation may cause loss of function related to both injury and illness.For example, an inflamed joint may not move properly, or a respiratory infection causing signs of inflammation in the lungs can make it hard to breathe.

Acute inflammation occurs at the onset of an injury that lasts for several days. It has two components:

• Thecellular component,in which first-line white blood cells (leukocytesandmacrophages) are activated and recruited to the site of the injury
• Thevascular phase,in which blood vessels open (dilate) and tissues swell to accommodate the rapid influx of immune cells and antimicrobial chemicals

Additional Signs and Complications

When inflammation is severe, it may cause more signs and symptoms, including:

• Exhaustion
• Fever
• A general feeling of sickness
• Trouble sleeping

Inflammation caused by an illness may lead to dangerous complications, including a condition calledsepsis. This condition happens when the body's immune system overwhelmingly responds to a serious infection and causes significant damage to the body’s organs and tissues.

What Causes Inflammation?

The causes of inflammation can be broadly classified as:

• Biological (e.g., infections, diseases, and abnormal immune responses, includingautoimmune diseases,atopy,allergy, and drug hypersensitivity)
• Chemical (e.g., poisons, toxins, and alcohol)
• Physical (e.g., injuries, burns, frostbite, or radiation exposure)

Acute and chronic inflammation can have different causes.

Acute Inflammation

Possible causes of acute inflammation include:

• Injuries
• Acute infections or illnesses (e.g., skin infection, insect bites or stings, colds and flus)
• Allergens
• Toxin exposures
• Foreign body ingestion

Chronic Inflammation

Possible causes of chronic inflammation include:

• Organ transplant rejection
• Chronic disease (e.g., inflammatory bowel disease, rheumatoid arthritis, asthma, heart disease, diabetes, cancer)
• Untreated or recurrent infections
• Lifestyle factors (e.g., obesity, alcohol use, heavy exercise, high stress, smoking)
  

How to Measure Inflammation

No single test can diagnose inflammation or the conditions that cause it. Instead, your healthcare provider will consider your symptoms when deciding what treatment is needed.

Your provider will start by taking a complete medical history and doing a physical examination. They may also want to do bloodwork and imaging studies to check for specific conditions that could be causing inflammation.

Blood Tests

Blood tests can look for biological markers that show there is inflammation in the body. However, these tests are considered informative rather than diagnostic. They help give your healthcare provider clues as to what’s going on but do not necessarily point to a single cause.

Tests your healthcare provider may want to do to check inflammation levels include:

• C-reactive protein(CRP): CRP is a protein naturally produced in the liver in response to inflammation. High levels of CRP are common in people with chronic inflammation, inflammatory diseases, and acute inflammation.
• Erythrocyte sedimentation rate(ESR): ESR testing is usually done to identify whether inflammation is occurring. This level is usually high with certain chronic inflammatory diseases, like lupus.

Imaging

Imaging tests can sometimes be used to look for specific injuries or problems inside the body that can cause inflammation.

Your provider might use these imaging tests to look for causes of inflammation in the body:

• MRI with gadolinium enhancement
• Ultrasound with power doppler
• FDG PET-CT
• Nuclear imaging

How Is Inflammation Treated?

Treatment will depend on the specific disease or ailment and the severity of symptoms.

Acute Inflammation

For general acute inflammation, your healthcare provider may recommend:

• Nonsteroidal anti-inflammatory drugs(NSAIDs): NSAIDs are usually the first-line treatment for short-term pain and inflammation. Most of these medications are available over the counter (OTC), and include aspirin, ibuprofen, and naproxen. Your healthcare provider can also prescribe prescription-strength NSAIDs for certain inflammatory conditions. Certain people should not take NSAIDs (even OTC NSAIDs), such as people with a history of chronic kidney disease or who are taking blood thinners (anticoagulation therapy).
• Corticosteroids: This is a type of steroid commonly used to treat swelling and inflammation. Corticosteroids are available in pill form and as injections. These drugs are only prescribed for a short time because they can cause serious side effects.
• Topical medications: Topicals, including analgesics and steroids, can help with acute and chronic pain and inflammation of the skin and joints, without the side effects of oral treatments. They are also helpful for managing long-term inflammation when they contain an NSAID, such as diclofenac or ibuprofen.
• Antibiotics: If inflammation is caused by a bacterial infection, antibiotics may be necessary. The antibiotic used and the course of treatment will depend on the infection.

Chronic Inflammation

In addition to treating joint pain and inflammation, medications for inflammatory diseases can help to prevent the disease from getting worse or at least help slow it down.Medications may include:

• Disease-modifying anti-rheumatic drugs (DMARDs), such as Rheumatrex (methotrexate), Azulfidine (sulfasalazine), and Arava (leflunomide)
• Biologic drugs, such as Enbrel (etanercept), Humira (adalimumab), and Orencia (abatacept)
• Anti-malarial drugs, such as hydroxychloroquine
• Statins
• Diabetes medications

Many medications used to treat inflammatory diseases can cause side effects, so it is important to see your healthcare provider regularly while you’re on them.

Ways to Reduce Inflammation

Over time, chronic inflammation can cause changes in organs that may increase the risk of heart attack, cancer, and other age-related diseases. Chronic inflammation is associated with chronic conditions likediabetes,heart disease,COPD, orHIV.

Fortunately, there are several changes to your lifestyle that you can make to prevent and reverse chronic inflammation, such as:

• Getting at least 20 minutes of moderate exercise per day
• Using stress-reduction techniques like mindfulness meditation
• Quitting smoking
• Maintaining a weight that supports your health
• Following an anti-inflammatory diet
• Drinking water, tea, coffee, milk, acidic juices, and healthful smoothies andlimiting sugary drinks and sodas (red wine in moderation may have anti-inflammatory benefits)
  

Summary

Inflammationis a process in your body that makes protective substances (likewhite blood cells) in response to something like an infection or injury. Inflammation can be short-term (acute) or long-term (chronic). The cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. When it's chronic, inflammation can also make you feel tired and affect your sleep.

You may not know for sure what's causing inflammation without seeing your provider. Once you know the underlying cause, you can take steps to lower inflammation and possibly prevent it.