What causes allergies?

You have an allergy when your body overreacts to it that does not cause problems for most people. These things are called allergens.

These substances when they enter the body through the air (pollen), through the nose (perfumes, cleaners), mouth (food) or through the skin are detected by some people as foreign to the body and a reaction occurs that causes the symptoms of the allergies.

Sometimes the term “hay fever” is used to describe an allergic reaction to allergens in the air. The body’s overreaction to allergens is what produces the symptoms.

Hay fever allergy symptoms

  • Discharge from the nose
  • Crying eyes
  • Stinging in the nose, eyes and roof of the mouth
  • Sneeze
  • Stuffy nose
  • Pressure on the nose and cheekbones
  • Ear congestion
  • Eye bags
  • Stinging

What are the most common allergens?

Pollen from trees, lawns, and weeds. Allergies that occur during the spring (late April and May) are often due to tree pollen. Allergies that occur in the summer (late May through mid-July) are often due to pollen on the lawn. Allergies that occur in the fall (late August until the first snow) are often due to ragweed.

Mold. Mold is common in places where water collects, such as shower curtains, window trim, and damp basements. It can also be found in rotten logs, hay, commercial peat moss, rubbish piles, and tree leaf litter. This allergy is usually worse in wet and humid weather.

Animal dander. Pieces of animal fur and fur are both allergens. You can be exposed to animal dander when dealing with an animal or if it is contained in house dust.

Dust. Many allergens, including tiny arachnids, are in the dust. These are little living creatures found in bedding, mattresses, rugs, and upholstered furniture. They live in tiny cells of dead tissue and other things found in house dust.

Things that can make your allergy symptoms worse

  • Aerosol sprays
  • Air pollution
  • Cold temperatures
  • Humidity
  • Irritating gases
  • Smoke of the tabacco
  • Wind
  • Wood smoke

How can I avoid allergens?

Pollen. Take a shower or bath to get rid of pollen and other allergens on your hair or skin before bed. Avoid going outside, especially on dry and windy days. Keeping windows and doors closed can be helpful, just as using air conditioning in your home and car can be helpful.

Mold. You can reduce the amount of mold in your home by removing indoor plants, frequently cleaning shower curtains, bathroom windows, damp walls, areas with dry rot, and indoor garbage cans. Use a mixture of water and bleach to kill mold.

Don’t put rugs in bathrooms or other damp rooms, and use mold-proof paint instead of wallpaper. Lowering the humidity in your home to 50% or less can also help.

Animal dander. If your allergies are severe, you may need to get rid of your pets or at least keep them outside. Dog or cat dander is often in house dust and takes 4 weeks or more to extinguish, so an attempt to remove your pet from your home for a short period of time may not help.

Dust. You can reduce tiny arachnids in dust by following the suggestions in the chart below.

Tips for reducing dust and tiny arachnids


  • Remove cloth curtains, feather pillows, upholstered furniture, duvets that cannot be washed, and stuffed toys.
  • Substitute linoleum or wood for rugs. Polished floors are better.
  • Wipe the floor frequently with a damp blanket and wipe the surfaces with a damp cloth.
  • Vacuum regularly with a machine that has a high-efficiency air filter.
  • Vacuum cloth furniture and curtains, as well as floors.
  • Install a high-efficiency air purifier or electrostatic filter.
  • Wash carpets and upholstery with a special cleaner, such as benzyl benzoate or tannic acid spray.
  • Wash all bedding in hot water (over 130ºF) every 7 to 10 days.
  • Do not use padded mattress protectors.
  • Cover mattresses and pillows with plastic liners.
  • Lower the humidity in your home


Treatment of hay fever allergies


Antihistamines help reduce coryza, runny nose and itching from allergies. These are most helpful if used before being exposed to allergens. Some antihistamines can be bought without a prescription. These relieve symptoms in the same way as prescription drugs, but they tend to cause dizziness and a dry mouth. The result is usually achieved after 1 to 2 weeks of regular use. Antihistamines that require a prescription from your doctor are less likely to cause tiredness or dry mouth.


Decongestants temporarily help relieve congestion in the nose caused by allergies. These come in the form of tablets, nasal sprays, and nasal drops. It is best to use them only for a short time. Nasal sprays and drops should not be used for more than 3 days because they can create dependency on the drug. This causes the person to feel congested when trying not to use it anymore. Decongestants can be purchased without a prescription. However, decongestants can raise your blood pressure, so it is a good idea to talk to your doctor before using them.

Medicines in aerosols

Cromolyn sodium is a nasal spray that helps reduce allergy symptoms. This helps to avoid the body’s reaction to allergens. It does not start to work for 2 to 4 weeks after you start using it. Your doctor may recommend cromolyn if your allergies are serious or if other medications don’t work. Cromolyn is also available without a prescription.

Nasal steroid sprays reduce the reaction of the nasal membranes to allergens that have been inhaled. This helps to relieve inflammation in the nose so that the person feels less stuffy. These are distributed in the form of nasal sprays that can be prescribed by your doctor. The results are not noticeable until after 2 weeks of using them.

Oral corticosteroids

Your doctor may prescribe steroid tablets for a short time or give you a steroid injection if your symptoms are severe or if other medications are not working for you.

Eye drops

Eye drops. If your other medications are not working enough for your itchy and watery eyes, your doctor may prescribe eye drops.

Allergy shots

Allergy shots (also called immunization treatments) contain a small amount of allergens. These are administered according to an established plan, so that the body gets used to these agents and does not react to them.