Inflammation is the body's attempt at self-protection; the aim being to remove harmful stimuli, including damaged cells, irritants, or pathogens - and begin the healing process.
When something harmful or irritating affects a part of our body, there is a biological response to try to remove it, the signs and symptoms of inflammation, specifically acute inflammation, show that the body is trying to heal itself.
Inflammation does not mean infection, even when an infection causes inflammation. Infection is caused by a bacterium, virus or fungus, while inflammation is the body's response to it.
Contents of this article:
- What is inflammation?
- Inflammation helps wounds heal
- What is the difference between chronic inflammation and acute inflammation?
- What happens during acute inflammation?
- Acute and chronic inflammation compared
- Why does inflammation cause pain?
- Autoimmune disorders and inflammation
- Possible treatments for inflammation
- Some herbs have anti-inflammatory properties
You will see introductions at the end of some sections to any recent developments that have been covered by MNT's news stories. Also look out for links to information about related conditions.
Fast facts on inflammation
Here are some key points about inflammation. More detail and supporting information is in the main article.
- Inflammation is the body's attempt at self-protection to remove harmful stimuli and begin the healing process.
- Inflammation is part of the body's immune response.
- The first stage of inflammation is often called irritation, which then becomes inflammation - the immediate healing process.
- Inflammation is followed by suppuration (discharging of pus). Then there is the granulation stage, the formation in wounds of tiny, rounded masses of tissue during healing.
- Acute inflammation - starts rapidly (rapid onset) and quickly becomes severe.
- Chronic inflammation - this means long-term inflammation, which can last for several months and even years.
- Our infections, wounds and any damage to tissue would never heal without inflammation - tissue would become more and more damaged and the body, or any organism, would eventually perish.
- Chronic inflammation can eventually cause several diseases and conditions, including some cancers, rheumatoid arthritis, atherosclerosis, periodontitis, and hay fever.
- Although scientists know that inflammation plays a key role in heart disease and several other illnesses, what drives inflammation in the first place is still a mystery.
- It should be remembered that inflammation is part of the healing process. Sometimes reducing inflammation is necessary, but not always.
What is inflammation?
The word inflammation comes from the Latin "inflammo", meaning "I set alight, I ignite".
Inflammation is part of the body's immune response. Initially, it is beneficial when, for example, your knee sustains a blow and tissues need care and protection. However, sometimes inflammation can cause further inflammation; it can become self-perpetuating. More inflammation is created in response to the existing inflammation.
Plaque in coronary artery disease linked to inflammation - scientists from Stanford University, California, linked 25 new genetic regions to coronary artery disease. They found that people with coronary artery disease, the leading cause of death globally, are most likely predisposed to the disease because they have gene variants linked to inflammation.
Inflammation helps wounds heal
Our immediate reaction to a swelling is to try to bring it down. Bearing in mind that inflammation is an essential part of the body's attempt to heal itself, patients and doctors need to be sure that the treatments to reduce swelling are absolutely necessary and to not undermine or slow down the healing process.
The first stage of inflammation is often called irritation, which then becomes inflammation - the immediate healing process. Inflammation is followed by suppuration (discharging of pus). Then there is the granulation stage, the formation in wounds of tiny, rounded masses of tissue during healing. Inflammation is part of a complex biological response to harmful stimuli. Without inflammation, infections and wounds would never heal.
Neuroscientists at the Lerner Research Institute at the Cleveland Clinic in Ohio found that inflammation actually helps to heal damaged muscle tissue. Their findings clash with how sportspeople with inflammation are treated - health professionals always try to control the inflammation to encourage healing. The researchers say their findings may lead to new therapies for acute muscle injuries caused by freeze damage, medications, chemicals and trauma.
Lan Zhou, M.D., Ph.D., said that patients should be very closely monitored when therapies to combat inflammation are used to make sure that the benefits of inflammation are not completely eliminated.
Inflammation is part of our innate immunity
Our innate immunity is what is naturally present in our bodies when we are born, and not the adaptive immunity we get after an infection or vaccination. Innate immunity is generally non-specific, while adaptive immunity is specific to one pathogen:
Whooping cough vaccine - example of immunity being specific to one pathogen
After being vaccinated for whooping cough (pertussis), we develop immunity to Bordetella pertussis or Bordetella parapertussis, types of bacteria that cause pertussis. This is an example of adaptive immunity - the immunity was not there before receiving the vaccine.
Inflammation is seen as a mechanism of innate immunity.
What is the difference between chronic inflammation and acute inflammation?
Acute inflammation - starts rapidly (rapid onset) and quickly becomes severe. Signs and symptoms are only present for a few days, but in some cases may persist for a few weeks.
Examples of diseases, conditions, and situations which can result in acute inflammation include:
- Acute bronchitis
- Infected ingrown toenail
- Sore throat from a cold or flu
- A scratch/cut on the skin
- Exercise (especially intense training)
- Acute appendicitis
- Acute dermatitis
- Acute tonsillitis
- Acute infective meningitis
- Acute sinusitis
- A blow.
Chronic inflammation - this means long-term inflammation, which can last for several months and even years. It can result from:
- Failure to eliminate whatever was causing an acute inflammation
- An autoimmune response to a self antigen - the immune system attacks healthy tissue, mistaking it (them) for harmful pathogens
- A chronic irritant of low intensity that persists.
Examples of diseases and conditions with chronic inflammation include:
- Chronic peptic ulcer
- Rheumatoid arthritis
- Chronic periodontitis
- Ulcerative colitis and Crohn's disease
- Chronic sinusitis
- Chronic active hepatitis (there are many more).
Our infections, wounds and any damage to tissue would never heal without inflammation - tissue would become more and more damaged and the body, or any organism, would eventually perish.
However, chronic inflammation can eventually cause several diseases and conditions, including some cancers, rheumatoid arthritis, atherosclerosis, periodontitis, and hay fever. Inflammation needs to be well regulated.
On the next page we look at what happens during acute inflammation, the comparison of acute and chronic inflammation and why it causes pain. On the final page we discuss treatments for inflammation.