Allergies: Types, Symptoms, Causes and Treatment Info

Author: Disabled World (DW)
Updated/Revised Date: 31 Jul 2026

Table of Contents:
Synopsis - Definition - About This Section - FAQs - Publications - Subtopics

Synopsis

Learn about allergy types, symptoms, causes and treatments, including airborne allergens, the role of histamine and vitamins that may ease reactions.

At a Glance

• 1 - Airborne allergy is the most common form, producing sinus related symptoms such as sneezing, a runny nose, and itchy eyes.
• 2 - Not every reaction or intolerance is a true allergy, and severe cases can lead to a life-threatening reaction called anaphylaxis.
• 3 - Quercetin, a flavonoid antioxidant, is noted for its ability to block the release of histamines and reduce allergy symptoms.
• 4 - According to CDC data cited on the page, about 7.5 percent of people had diagnosed hay fever and 12.0 percent reported skin allergies in the past 12 months.

Topic Definition

Allergy

An allergy is a hypersensitivity disorder in which the immune system overreacts to a normally harmless substance, treating it as a threat and mounting a defensive response. When the body encounters one of these triggers, known as an allergen, it can release large amounts of histamine and other chemicals that inflame surrounding tissue, producing familiar symptoms such as sneezing, a runny or stuffy nose, red and watery eyes, itching, hives, eczema, or, in the case of asthma, difficulty breathing. Common allergens include pollen, mold, dust, animal dander, insect stings, and certain foods, and reactions range from mildly annoying to, in rare and severe cases, a life threatening emergency called anaphylaxis. Because each person's immune system and biology differ, allergies vary widely in their triggers, severity, and in how well they respond to treatments such as antihistamines.

Overview

NOTE: This section is mainly on respiratory system allergies - For food allergy information, click here.

An allergy is a hypersensitivity disorder of the immune system. Symptoms include red eyes, itchiness, and runny nose, eczema, hives, or an asthma attack. Allergies can play a major role in conditions such as asthma. In some people, severe allergies to environmental or dietary allergens or to medication may result in life-threatening reactions called anaphylaxis. Food allergies and reactions to the venom of stinging insects such as wasps and bees are more often associated with these severe reactions. Not all reactions or intolerances are forms of allergy.

Allergens that most frequently cause problems are: pollen, mold, dust, foods, animal dander, insect bites, insect spores, viruses, and bacteria. Some of the most common allergy symptoms known as the seasonal allergies such as hay fever which include itchy watery eyes, runny nose, and sneezing aspects of allergenic symptoms. Furthermore, other cases of allergy feature more serious symptoms that can be more harmful and troublesome such as absent-mindedness, dizziness, trouble swallowing, nausea, constipation, diarrhea, skin rashes, vertigo, vomiting, and other serious cases of health issues that may spring from how the body deals with the allergen itself.

Normally, though experience, the human body learns to defend itself. That is, by attacking a foreign substance that has invaded and, harming the body by producing antibodies. The best known of these antibodies are called histamines. Occasionally, the immune system mistakenly recognizes a foreign substance, to be harmful, when it is not. This can lead to the overproduction of histamines specially designed to destroy the specific foreign substance.

If the overproduction of the histamines is large enough the surrounding tissue is also damaged resulting in sneezing, a stuffy head, sniffing, stuffed-up head, read and watery eyes. The sinuses as the hay fever tend to affect certain systems of the body or even a skin rash which can be irritating.

What Causes Some Symptoms?

Take for instance Airborne allergy which, however, is the most common form of allergy and tend to feature the most common form of symptom as well. Most of these symptoms are related to the sinuses, like hay fever, tend to impact those systems of the body. Sneezing, a clogged and runny nose, itchiness in the eyes and throat, coughing, postnasal drip, and swollen eyes (a symptom called "conjunctivitis") are all parts of the airborne allergy symptom repertoire.

Why Do These Symptoms Occur?

Most times, the allergic reaction is coupled with a portion of an allergen. In other words, if the allergen is known for entering the lungs, it will likely attack portions of the body related to the lungs and to the breathing. An airborne allergy, hence, is likely to attach itself to the breathing apparatus and will cause coughing or the nose to run because of the way it affects the system. A person with Allergies is burdened with an overprotective immune system and is forever on guard against everyday things that don't usually bother the rest of us. It might be a cute affectionate kitten, a patch of green grass, a slice of fresh garden tomato.

Some of us can roll in poison ivy and come out without any problems, whilst others can merely brush up against a few leaves of the stuff, and they are scratching for weeks. In most cases, allergies are more annoying than are infirmity. To the extreme allergy sufferers, life can be pure misery or even death.

Main Types of Allergic Reactions

Food, mold, animal dander, pollen, or dust can cause an immediate reaction to an allergy attack. When your body responds to the invasion, the body release histamine from the irritated area such as the skin, nasal and bronchial areas. Allergens combine with healthy cells in your body, which attacks the healthy cells; this is common in upper gastrointestinal attack.

Allergens invade the immune system and can cause injury to cells though out the body. T-cells become activated and result in an inflammation of the affected area. This is exemplified by a rash caused by poison ivy. Instead of the antibodies binding to the cell components as they do in type 2 allergies, the antibodies bind to the receptors on the surface of the cells.

We all carry a heavy load of various stress factors that slowly wear out our immune systems, over the years, making us more susceptible to allergy attacks. We are exposed to many more environmental pollutants and industrial toxins. No matter what type of allergy you are suffering from, there is a good chance that you can find relief from it. You can fight allergies with vitamins and over the counter products. Common Vitamins and over the counter products can help with Allergies such as vitamin A, vitamin B, vitamin C, vitamin E, Vitamin B5, Glucosamine, Antioxidants, Allergy Aid, and Quercetin.

• Vitamin A: A known antioxidant and can assist the human body in the healing process. Vitamin A is stored in the liver and fat cells of the human body and can reach toxic levels. DO NOT take more than the recommended dosage of vitamin A. Up to one-third of older people can no longer absorb vitamin B from their food. Vitamin B is needed to form red blood cells and keep nerves healthy.
• Vitamin C: Nature's protective nutrient, essential for defending the body against pollution and infection and enhances the bodies immune system. Vitamin C, also known as ascorbic acid, is a water-soluble vitamin. Unlike most mammals, humans can't make their own vitamin C. Therefore, we must obtain vitamin C through our diet. Beta Carotene protects the mucus membranes of the mouth, nose, throat, and lungs. It also helps protect vitamin C from oxidation, which enables it to perform at optimum efficiency. Biologically, beta-carotene is most important as the precursor of vitamin A. It also has anti-oxidant properties and may help in preventing cancer and other diseases.
• Vitamin E: Protects the lung tissue from inhaled pollutants and aids in the functioning of the immune system. Alpha-tocopherol is the only form of vitamin E that is actively maintained in the human body and is, therefore, the form of vitamin E found in the largest quantities in the blood and tissue. Pantothenic acid, also known as vitamin B5, is essential to all forms of life. Pantothenic acid is found throughout living cells in the form of coenzyme A (CoA), a vital coenzyme in numerous chemical reactions. Many find Pantothenic Acid to be very helpful against allergy symptoms. It is another form of nontoxic B vitamins. Pantothenic Acid is critical in the metabolism and synthesis of carbohydrates, proteins, and fats.
• Glucosamine: An anti-inflammatory and may give some relief from allergy symptoms. Substances called antioxidants can neutralize free radical by pairing up or binding with the free radical elections, thus inhibiting them from damaging cells in the human body. Allergy Aid supplies 9 beneficial herbs to help provide temporary relief of respiratory allergies. The natural action of these specific Herb's help to open bronchial tubes and ease breathing.
• Quercetin: Flavonoids are powerful antioxidants and can reduce inflammation boost the immune system and strengthen blood vessels and improve circulation. Quercetin is also known for its ability to block the release of histamines, thus reducing or preventing allergy symptoms.

How are Allergy Symptoms Cured?

An allergy symptom can be cured in several ways, depending on the actual system it affects and how drastically the body is affected. Many people can simply take, for example, an antihistamine for a hay fever type allergy and go about their day, while others simply will not respond to the antihistamine. It is really essential for the matter of the biological makeup of the allergy sufferer in terms of how they react to certain medications and how much medication is needed to cure the allergy symptom.

Allergy Facts and Statistics

• Percent with diagnosed hay fever in the past 12 months: 7.5%.
• Percent with reported food allergies in the past 12 months: 5.6%.
• Percent with reported skin allergies in the past 12 months: 12.0%.
• Number with diagnosed hay fever in the past 12 months: 17.6 million.
• Number with reported food allergies in the past 12 months: 4.1 million.
• Number with reported skin allergies in the past 12 months: 8.8 million.
• Percent with reported respiratory allergies in the past 12 months: 10.6%.
• Number with reported respiratory allergies in the past 12 months: 7.8 million.
• Number of visits to physician offices with a primary diagnosis of allergic rhinitis: 11.1 million.

Above statistics from U.S. CDC. According to Allergy UK, one in four people in the UK suffers from an allergy at some point in their lives. The numbers are increasing every year, and up to half of those affected are children.

Frequently Asked Questions

What is the difference between an allergy and an intolerance

An allergy involves the immune system reacting to a substance, while an intolerance is usually a digestive or chemical response that does not involve the immune system.

How are allergies diagnosed

Doctors often use skin prick tests, blood tests that measure specific antibodies, and a review of symptoms and history to identify triggers.

Can allergies develop later in life

Yes, allergies can appear at any age, and some people develop new sensitivities as adults even to things that never troubled them before.

What is anaphylaxis and how is it treated

Anaphylaxis is a severe, rapid, and potentially life threatening allergic reaction that is treated with emergency adrenaline and urgent medical care.

Are allergies hereditary

A tendency toward allergies often runs in families, though the specific allergens a person reacts to can differ from those of their relatives.

Can you outgrow an allergy

Some childhood allergies, particularly to certain foods such as milk or egg, may fade with age, while others can persist for life.

How can I reduce allergens in my home

Regular cleaning, washing bedding in hot water, using dust mite covers, controlling humidity to limit mold, and keeping pets out of bedrooms can all help.

Curated and edited by Ian C. Langtree, Founder & Editor-in-Chief, Disabled World. This section is maintained by the Disabled World editorial team.

Last updated: 31 Jul 2026