Inflammatory Conditions

What inflammation is

Inflammation is how the immune system responds to injury or infection. Blood vessels widen and become leaky, immune cells arrive, and the classic signs appear: redness, heat, swelling, pain and loss of function. In acute inflammation, this process clears the threat and resolves within days.

In chronic inflammation, the process continues for months or years. Causes include:

• an immune system that attacks the body's own tissues (autoimmunity)
• faulty innate immune signaling that switches inflammation on without a trigger (autoinflammation)
• persistent triggers such as crystals (gout), allergens (asthma) or toxins (smoking)
• ongoing infection

Chronic low-grade inflammation is also linked to obesity, atherosclerosis, type 2 diabetes and some cancers.

Types of inflammatory conditions

Non-infectious gastroenteritis

Not all inflammation of the stomach and intestines is caused by infection. Noninfectious gastroenteritis can result from inflammatory and autoimmune conditions such as Crohn's disease, ulcerative colitis, celiac disease and eosinophilic gastroenteritis, from medicines including NSAIDs (nonsteroidal anti-inflammatory drugs) and chemotherapy, and from radiation, food allergies and toxins. It often appears as part of a cluster of symptoms, such as diarrhea with joint pain or rash.

Common symptoms

Symptoms depend on which tissues are affected, but many inflammatory conditions share:

• fatigue, often profound
• low-grade fever and night sweats
• joint pain, swelling and stiffness
• muscle aches
• rashes and skin changes
• abdominal pain and diarrhea
• weight loss and loss of appetite
• dry eyes or mouth, mouth ulcers, red eyes

Many conditions have flares (worse periods) and remissions.

Risk factors

• genetics and family history
• female sex for many autoimmune diseases, such as lupus and rheumatoid arthritis
• smoking (rheumatoid arthritis, Crohn's disease, psoriasis)
• obesity
• infections that may trigger autoimmunity
• environmental exposures such as silica and air pollution

Diagnosis

• History and examination: pattern of symptoms over time.
• Inflammatory markers: C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). These show inflammation is present but not its cause.
• Blood counts, kidney and liver function, urinalysis.
• Autoantibodies: ANA, rheumatoid factor, anti-CCP, ANCA and others, interpreted with care because low-level positives are common in healthy people.
• Disease-specific tests: fecal calprotectin and colonoscopy for IBD, skin biopsy, imaging of joints or blood vessels.
• Genetic testing for some autoinflammatory syndromes.

Treatment

• NSAIDs for pain and inflammation in arthritis. Follow the label dose and check with a doctor if you have kidney, stomach or heart problems.
• Corticosteroids for rapid control of flares, used at the lowest dose for the shortest time.
• Conventional disease-modifying drugs: methotrexate, sulfasalazine, hydroxychloroquine, azathioprine, mycophenolate.
• Biologics: TNF inhibitors, IL-6, IL-17, IL-23 and IL-1 blockers, B-cell therapies, and others targeted to specific pathways.
• JAK inhibitors: oral targeted drugs for several conditions.
• Colchicine for gout and familial Mediterranean fever.

Because many treatments suppress the immune system, patients need vaccinations, screening for infections such as tuberculosis and hepatitis B, and regular monitoring.

Lifestyle

• stop smoking
• stay active, which reduces inflammation and joint stiffness
• maintain a healthy weight
• eat a balanced, Mediterranean-style diet
• get enough sleep and manage stress

Supplements and "anti-inflammatory diets" can complement but not replace proven medical treatment.

Complications

Uncontrolled chronic inflammation can cause joint destruction, organ damage (kidneys, lungs, eyes), higher cardiovascular risk, osteoporosis, anemia and, in some conditions, cancer risk. Treatment side effects include infections and medicine-specific risks.

Frequently asked questions

What are inflammatory conditions?

They are diseases in which inflammation, the immune system's normal protective response, becomes persistent or misdirected and damages tissues. Examples include rheumatoid arthritis, lupus, inflammatory bowel disease, psoriasis, vasculitis, asthma and gout.

What are the symptoms of chronic inflammation?

Common symptoms include fatigue, low-grade fever, joint pain and stiffness, muscle aches, rashes, digestive problems such as diarrhea and abdominal pain, and weight loss. Symptoms often come in flares and depend on which organs are affected.

What is the difference between autoimmune and autoinflammatory diseases?

In autoimmune diseases, the adaptive immune system makes antibodies or T cells that attack the body's own tissues, as in lupus. In autoinflammatory diseases, the innate immune system switches on inflammation without a specific target, causing recurrent fevers and inflammation, as in familial Mediterranean fever.

What blood tests show inflammation?

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are the main tests. They show that inflammation is present but not its cause. Doctors combine them with symptoms, examination, autoantibody tests and imaging to make a diagnosis.

Can diet reduce inflammation?

A Mediterranean-style diet rich in vegetables, fruit, whole grains, fish and olive oil, along with weight loss if needed, can lower inflammatory markers and may ease symptoms. Diet is a helpful addition but does not replace medical treatment for inflammatory diseases.