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Inflammation is part of the body’s defense mechanism and plays a role in the healing process.
When the body detects an intruder, it launches a biological response to try to remove it.
The attacker could be a foreign body, such as a thorn, an irritant, or a pathogen. Pathogens include bacteria, viruses, and other organisms, which cause infections.
Sometimes, the body mistakenly perceives its own cells or tissues as harmful. This reaction can lead to autoimmune diseases, such as type 1 diabetes.
Experts believe inflammation may contribute to a wide range of chronic diseases. Examples of these are metabolic syndrome, which includes type 2 diabetes, heart disease, and obesity.
People with these conditions often have higher levels of inflammatory markers in their bodies.
In this article, find out more about why inflammation happens, its symptoms, and ways to resolve it.
There are two main types of inflammation: acute and chronic.
An injury or illness can involve acute, or short-term, inflammation.
There are five key signs of acute inflammation:
- Pain: This may occur continuously or only when a person touches the affected area.
- Redness: This happens because of an increase in the blood supply to the capillaries in the area.
- Loss of function: There may be difficulty moving a joint, breathing, sensing smell, and so on.
- Swelling: A condition call edema can develop if fluid builds up.
- Heat: Increased blood flow may leave the affected area warm to the touch.
These signs are not always present. Sometimes inflammation is “silent,” without symptoms. A person may also feel tired, generally unwell, and have a fever.
Symptoms of acute inflammation last a few days. Subacute inflammation lasts 2–6 weeks.
Chronic inflammation can continue for months or years. It either has or may have links to various diseases, such as:
- cardiovascular disease (CVD)
- arthritis and other joint diseases
- chronic obstructive pulmonary disease (COPD)
- rheumatoid arthritis
The symptoms will depend on the disease, but they may include pain and fatigue.
When inflammation is present in the body, there will be higher levels of substances known as biomarkers.
An example of a biomarker is C-reactive protein (CRP). If a doctor wants to test for inflammation, they may assess CRP levels.
CRP levels tend to be higher in older people and those with conditions such as cancer and obesity. Even diet and exercise may make a difference.
Inflammation happens when a physical factor triggers an immune reaction. Inflammation does not necessarily mean that there is an infection, but an infection can cause inflammation.
Acute inflammation can result from:
- exposure to a substance, such as a bee sting or dust
- an injury
- an infection
When the body detects damage or pathogens, the immune system triggers a number of reactions:
- Tissues accumulate plasma proteins, leading to a buildup of fluid that results in swelling.
- The body releases neutrophils, a type of white blood cell, or leukocyte, which move toward the affected area. Leukocytes contain molecules that can help fight pathogens.
- Small blood vessels enlarge to enable leukocytes and plasma proteins to reach the injury site more easily.
Signs of acute inflammation can appear within hours or days, depending on the cause. In some cases, they can rapidly become severe. How they develop and how long they last will depend on the cause, which part of the body they affect, and individual factors.
Some factors and infections that can lead to acute inflammation include:
- acute bronchitis, appendicitis and other illnesses ending in “-itis”
- an ingrown toenail
- a sore throat from a cold or flu
- physical trauma or wound
Chronic inflammation can develop if a person has:
Sensitivity: Inflammation happens when the body senses something that should not be there. Hypersensitivity to an external trigger can result in an allergy.
Exposure: Sometimes, long-term, low-level exposure to an irritant, such as an industrial chemical, can result in chronic inflammation.
Autoimmune disorders: The immune system mistakenly attacks normal healthy tissue, as in psoriasis.
Autoinflammatory diseases: A genetic factor affects the way the immune system works, as in Behçet’s disease.
Persistent acute inflammation: In some cases, a person may not fully recover from acute inflammation. Sometimes, this can lead to chronic inflammation.
Factors that may increase the risk of chronic inflammation include:
- older age
- a diet that is rich in unhealthful fats and added sugar
- low sex hormones
- sleep problems
Long-term diseases that doctors associate with inflammation include:
- chronic peptic ulcer
- rheumatoid arthritis
- ulcerative colitis and Crohn’s disease
- active hepatitis
Inflammation plays a vital role in healing, but chronic inflammation may increase the risk of various diseases, including some cancers, rheumatoid arthritis, atherosclerosis, periodontitis, and hay fever.
The following table summarizes some key differences between acute and chronic inflammation.
|Cause||Harmful pathogens or tissue injury.||Pathogens that the body cannot break down, including some types of viruses, foreign bodies that remain in the system, or overactive immune responses.|
|Duration||A few days.||From months to years.|
|Outcomes||Inflammation improves, or an abscess develops or becomes chronic.||Tissue death, thickening, and scarring of connective tissue.|
It is essential to identify and manage inflammation and related diseases to prevent further complications.
Acute inflammation can cause pain of varying types and severity. Pain may be constant and steady, throbbing and pulsating, stabbing, or pinching.
Pain results when the buildup of fluid leads to swelling, and the swollen tissues push against sensitive nerve endings.
Other biochemical processes also occur during inflammation. They affect how nerves behave, and this can contribute to pain.
Treatment of inflammation will depend on the cause and severity. Often, there is no need for treatment.
Sometimes, however, not treating inflammation can result in life threatening symptoms.
During an allergic reaction, for example, inflammation can cause severe swelling that may close the airways, making it impossible to breathe. It is essential to have treatment if this reaction occurs.
Without treatment, some infections can enter the blood, resulting in sepsis. This is another life threatening condition that needs urgent medical treatment.
A doctor may prescribe treatment to remove the cause of inflammation, manage symptoms, or both.
For a bacterial or fungal infection, for example, they may prescribe antibiotics or antifungal treatment.
Here are some treatments specifically for treating inflammation:
Nonsteroidal anti-inflammatory drugs
Nonsteroidal anti-inflammatory drugs (NSAIDs) will not remove the cause of inflammation, but they can help relieve pain, swelling, fever, and other symptoms. They do this by countering an enzyme that contributes to inflammation.
Examples of NSAIDs include naproxen, ibuprofen, and aspirin. These are available to purchase online or over the counter. People should check first with a doctor or pharmacist to ensure they make the right choice.
People should only use NSAIDs long term if a doctor recommends them, as they can have adverse effects. Aspirin is not suitable for children.
Pain relief: Acetaminophen, including paracetamol or Tylenol, can relieve pain but does not reduce inflammation. These drugs allow the inflammation to continue its role in healing.
Corticosteroids, such as cortisol, are a type of steroid hormone. They affect various mechanisms involved in inflammation.
Corticosteroids can help manage a range of conditions, including:
- temporal arteritis
- inflammatory bowel disease (IBD)
- systemic lupus
- allergic reactions
They are available as pills, injections, in an inhaler, or as creams or ointments.
Long-term use of corticosteroids can be harmful. A doctor can advise on their risks and benefits.
Treatment for diseases that involve long-term inflammation will depend on the condition.
Some drugs act to repress the body’s immune reactions. These can help relieve symptoms of rheumatoid arthritis, psoriasis, and other similar autoimmune reactions. However, they can also leave a person’s body less able to fight an infection if it occurs.
People who have undergone transplant surgery also need to take immunosuppressant drugs to prevent their bodies from rejecting the new organ. They, too, need to take extra care to avoid exposure to infections.
Various herbal supplements may help manage inflammation.
Harpagophytum procumbens: Also known as devil’s claw, wood spider, or grapple plant, this herb comes from South Africa and is related to sesame plants. Some older research from 2011 has shown it may have anti-inflammatory properties. Various brands are available to purchase online.
Hyssop: People can mix this plant with other herbs, such as licorice, for the treatment of some lung conditions, including airway inflammation. However, the hyssop essential oil has led to life threatening convulsions in laboratory animals, so caution is necessary.
Ginger: People have long used ginger to treat dyspepsia, constipation, colic, and other gastrointestinal problems, as well as rheumatoid arthritis pain. Ginger is available fresh in groceries or online in supplement form.
Turmeric: Curcumin, the main ingredient in turmeric, may have benefits for arthritis, Alzheimer’s disease, and some other inflammatory conditions. Supplements with turmeric and curcumin are available online.
Cannabis: A cannabinoid called cannabichromene may have anti-inflammatory properties. People should check first if cannabis-related products are legal where they live.
Learn more here about anti-inflammatory supplements.
These herbs are not approved by the Food and Drug Administration (FDA) for medicinal use. Always talk to a doctor before using any herbal or other supplements.
Some foods contain nutrients that may help reduce inflammation.
- olive oil
- high fiber foods
- nuts, such as walnuts and almonds
- leafy greens, including spinach and kale
- fatty fish, such as salmon and mackerel
- fruit, including blueberries and oranges
The following may aggravate inflammation:
- fried foods
- highly processed foods
- foods and drinks with added sugar
- red meat
- unhealthful fats, such as saturated and trans fats
Diet alone will not control inflammation, but making suitable choices may help prevent it from getting worse.
Learn more here about the anti-inflammatory diet.
Inflammation is part of the process by which the immune system defends the body from harmful agents, such as bacteria and viruses. In the short term, it can provide a useful service, although it may also cause discomfort.
Long-term or chronic inflammation, however, can both lead to and result from some severe and possibly life threatening conditions.
People with tumors, rheumatoid arthritis, inflammatory bowel disease, drug reactions, and other health issues may have high levels of CRP, which is a sign of an inflammatory immune response.
As scientists learn more about the role of inflammation in disease, their findings could lead to more effective treatments for various illnesses that do not yet have a cure, such as type 1 diabetes.