Inflammation: causes and symptoms

How does inflammation develop?
Inflammation is a natural and non-specific reaction that takes place in the organism due to trauma, burn, lesion, viral or bacterial infection and other physically dangerous situations.

When something irritating or harmful to health affects a part of the body, a biological response occurs in an attempt to remove it.

The signs and symptoms of acute inflammation (or phlogosis) demonstrate that the body is seeking a cure on its own.

Inflammation is not synonymous with infection, even though it can cause inflammation.

An infection is the intrusion of bacteria, viruses or fungi, while phlogosis is the body’s response to this aggression.

What is the difference between acute and chronic inflammation?

Acute inflammation

Acute inflammation begins in several seconds to a few minutes after tissue injury, for example, as soon as one has suffered trauma to the knee.
The damage may be purely physical or result from the activation of an immune response.

Three main processes occur:

• Increase in blood flow due to dilation of the vessels (arterioles) that supply the tissues.
• Increasing capillary permeability, which allows proteins and blood to enter the interstitial space (between cells).
• Migration of neutrophils (and perhaps some macrophages) from capillaries and small veins to the interstitial space.

The first two effects are visible a few minutes after a scratch that does not tear open the skin.
At first, the visible sign appears as a pale red line.
After that, the tissue turns red a few millimeters next to the scratch as soon as the local blood flow increases.
In the end, edema is formed, which means that the zone swells due to the increase in fluid in the interstitial spaces in this area.

1) Margination
The endothelium of blood vessels is the inner lining of the arteries.
At the beginning, the neutrophils (a type of white blood cell) attach themselves to the endothelium of the blood vessels. The attachment occurs due to certain molecules called cell adhesion molecules (CAM), which are located on the surface of the neutrophils and on the endothelial cells of the injured tissue.
The connection takes place in two steps.

• In the first step, the adhesion molecules, called selectins, connect the neutrophils to the endothelium and the white blood cells begin to roll up on the surface of the blood vessels.
• In the second phase, the neutrophils form a closer connection on the endothelial cells.

Sometimes pus forms near the area where the acute inflammation exists, especially as long as a foreign body remains in the tissues.
Analysis of pus shows that it is full of neutrophils.

2) Diapedesis
Diapedesis is an exit of blood cells from veins and arteries through the walls of small-caliber vessels.

3) Chemotaxis
Chemotaxis is the approach or removal of a certain substance.
After the neutrophils leak out of the blood vessels, they are attracted to a high concentration of viruses and bacteria and thus directed to infection.

4) Phagocytosis
Neutrophils recognize viruses and bacteria, ingest them and incorporate them into the interior of bubbles, where they are then killed.

Chronic inflammation

Chronic inflammation is long-term inflammation. It can actually last for several months, even years, for example, many know the chronic inflammation of the prostate.
Possible causes of chronic inflammation:

• Inability to eliminate the cause of acute inflammation.
• An autoimmune reaction, that is, the immune system attacks healthy tissue, confusing it with harmful pathogenic organisms.
• An irritating substance comes into constant contact with the body.
• Examples of chronic inflammation are: asthma, chronic peptic stomach ulcer, tuberculosis, rheumatoid arthritis, Crohn’s disease, chronic sinusitis and chronically active hepatitis.

Infections, wounds and tissue damage do not heal without inflammation.

Nevertheless, chronic inflammation can ultimately cause various diseases: some tumors, rheumatoid arthritis, atherosclerosis and hay fever.
Eliminating chronic inflammation is much more difficult and takes much longer.
How many people suffer from chronic back pain or chronic sinusitis? If it were enough to take an anti-inflammatory to solve all problems, very many people would be happy and happy. Unfortunately, however, there are sometimes other reasons that do not allow a cure.
In the case of back, it can be posture or a problem of the feet that affects the spine or causes discomfort to organs and intestines.
As long as the cause is not eliminated, the inflammation persists despite the medication.

Confrontation

Acute inflammation
Causes: harmful bacteria or tissue injuries.
Prelude (when the inflammation begins): immediately.
Duration: short, only a few days.
Results: the inflammation improves (resolution), an abscess or chronic inflammation can develop.

Chronic inflammation
Causes: non-degradable pathogenic organisms that lead to persistent inflammation, infections caused by some types of virus, foreign bodies that are not removed, hyperactive reaction of the immune system.
Duration: a few months or years.
Results: tissue destruction, thickening and scarring in the connective tissue (fibrosis), cell death or tissue death (necrosis).

The five signs of acute inflammation

Inflammation manifests itself under five different signs:

• Pain – the inflamed area can be painful, especially if something presses on it. Some chemical substances that stimulate the nerve endings are released, making the area sensitive.
• Redness – this occurs because the capillaries are full of blood.
• Immobility – loss of function may occur.
• Swelling – caused by fluid retention.
• Edema – The area swells because the fluid accumulates in the interstitial spaces.
  Heat – the same reason why redness occurs, more blood in the affected areas feels warm when touched.

Why does inflammation cause pain?

When people have inflammation, it usually hurts, depending on the severity you feel pain, stiffness, malaise or agony.
The pain can be constant and stable.
The inflammation causes pain because the swelling presses on sensory nerve endings (nociceptors) that carry the pain signals to the brain. The nerve endings send pain signals to the brain throughout the day, however, the encephalon ignores most of them unless the pressure against the nerve endings increases.

Inflammation and autoimmune diseases

An autoimmune disease is a condition in which the body triggers an immune response against healthy tissue because it mistakes it for damaging and irritating pathogenic organisms. Consequently, the immune system triggers an inflammatory reaction.
There are hundreds of autoimmune diseases and almost all of them have inflammation as a characteristic sign. Some examples are listed here.

Rheumatoid arthritis – an inflammation of the joints, surrounding tissues and sometimes some body organs.

Ankylosing spondylitis – inflammation of the vertebrae, muscles, ligaments and also sacroiliac joints (between the coccyx and pelvis); it may cause a mild fever.

Celiac disease – inflammation and destruction of the mucous membrane of the small intestine.

Crohn’s disease – the gastrointestinal tract becomes inflamed. Inflammation is most common in the ileum (small intestine), but can occur in any area of the digestive tract, from the mouth to the anus.

Graves’ disease – one of the signs is goiter, when the thyroid gland is inflamed. Exophthalmos is an inflammation of the muscles behind the eyes.

Idiopathic pulmonary fibrosis – the role of this inflammation is poorly understood. Experts believe that idiopathic pulmonary fibrosis is caused by inflammation of the alveoli (small sacs inside the lungs). Nevertheless, the successes in treatment to reduce inflammation are often disappointing.

Lupus – inflammation can occur in joints, lungs, heart, kidneys and skin.

Psoriasis – there is inflammation of the skin. In some cases, the joints and surrounding tissues can also become inflamed, as in psoriatic arthritis.

Type 1 diabetes – inflammation is possible in different parts of the body if the diabetes is not well controlled.

Addison’s disease – inflammation of the adrenal glands.

Vasculitis – refers to a group of conditions in which inflammation ultimately destroys blood vessels, arteries and veins.

Graft rejection – there is a noticeable inflammation caused by the graft surgery. When the organ recipient’s immune system rejects the transplant, inflammation develops around the donated organ.

Various allergies – all allergies are characterized by inflammation. Asthma is an inflammation of the respiratory tract, in hay fever nose, ears and the pharyngeal mucosa swell, while people who are allergic to bee stings can develop severe and fatal inflammation that affects the whole body (anaphylaxis).

Factors contributing to inflammation

Many factors play a significant role in the formation and maintenance of inflammation in the body, including physical imbalance, diet, allergies, sleep deprivation, obesity, and age.

Physical condition. Incorrect alignment of the body and joints plays an important role in inflammatory diseases.
Shoulders turned inwards, a chest bent forward, and the outward rotation of the hips are problems of incorrect posture that cause pain or damage to areas that become inflamed as a result (Sahrmann 2001).

Poor nutrition. A very important factor contributing to inflammation is the Western diet, which is rich in saturated and unsaturated fat, simple carbohydrates, and animal proteins (Sears 2005; Appleton 2004; Meggs 2004).
The American Dietetic Association (ADA) advises against this diet, which promotes cancer, cardiovascular disease, cerebral infarction and other autoimmune diseases (ADA 2007).

Sensitivities and food allergies that contribute to inflammation. The most common food allergies involve gluten from grains, nuts or seafood.
Food intolerances can cause inflammatory reactions to certain foods; for example on dairy products, corn, soy, wheat, sugar and nuts (Meggs 2004).

Other allergens. In addition to food, there are other allergens such as chemicals, dust, mold and pollen that release neurotransmitters called histamines via the immune system, which trigger an inflammatory process in the blood vessels.
The allergic reaction may be mild (for example, itching, runny nose) or more severe (for example, increased blood pressure, swelling, shortness of breath). Air pollution, noise, and detergents can increase inflammation (Meggs 2004; Appleton 2004).

Insomnia. Lack of sleep is accompanied by inflammation.
Sleep is the period when the body regenerates both mentally and physically.
That’s why professionals recommend 7-9 hours of sleep each night to function optimally.
Studies indicate that this period of time is crucial for the biochemical balance of substances such as growth hormone and cortisol (Dement 2000).

Overweight. Biochemical balance disorders are also related to inflammation caused by excessive belly fat. Above a certain amount, the excess intra-abdominal fat produces substances that cause inflammation.

Advanced age. Another factor is age. With age, the level of interleukin increases sharply. It plays a role in the development of many age-related diseases, including heart disease, osteoporosis, Alzheimer’s disease and other cognitive disorders (Meggs 2004).

Physical and psychological stress factors

It is observed that the immune system is well equipped to deal with physical stressors such as microbes, ankle sprains, hay fever, etc.
What is not entirely clear, however, is the question of how the immune system reacts to an accumulation of other physical stressors: poor nutrition, lack of sleep, allergies or intolerances, poor posture and foreign bodies.
In addition, behavioral scientists have studied the effect of psychological and emotional stressors on physical health for about 80 years.

An important research finding has shown that psychological stressors pose a strong challenge to homeostasis, such as influenza or muscle lesions. (Linden 2004).
The body responds to physical, emotional, and psychological stress by releasing hormones such as epinephrine and norepinephrine, which prepare the body for certain actions.

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