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A 45-year-old member asked:

What causes asthma?

7 doctor answers23 doctors weighed in
Dr. Sean McGhee
Allergy and Immunology 24 years experience
Genes + environment: People with asthma usually are predisposed to be allergic. This is usually inherited, and so caused by your particular genes. However, this alone is not enough. There is also clearly an effect from the environment you live in. Exactly what in the environment is responsible is unknown, but is the object of much interest and research.
Dr. Joram Seggev
Specializes in Internal Medicine - Allergy & Immunology
Also infection: While 80% of asthma patients have allergies, there are patients whose asthma starts after they had a respiratory infection. Those infections can be due to viruses such as influenza (the real flu) or certain bacteria such as mycoplasma or chlamydia. Such patients are usually older and have no history of allergy. Still, patients who already have asthma and get infected, their asthma will get worse.
Dr. Michael Rupp
Allergy and Immunology 22 years experience
Allergies: The majority of childhood asthma is caused by allergies creating inflammation in the lungs which leads to narrowing of the air tubes in the lungs and trouble breathing. Infection certainly can cause symptoms that look like asthma. In children this often occurs after illnesses like RSV, influenza, parainfluenza, and even the common cold has been shown to have this effect.
Dr. John Chiu
Allergy and Immunology 58 years experience
Repair defect: Although over 50% of asthma is related to allergies, allergies do not cause asthma in everyone who is allergic. The current focus is on the malfunctioning repair mechanism in the epithelium of the airways which apparently is abnormal in people suffering from asthma. Many thing can trigger the damage (diesel particles, allergens, virus) the end result is narrowing of the airways. Sounds too complex
Dr. Joram Seggev
Specializes in Internal Medicine - Allergy & Immunology
The above mechanism may be the common denominator, it still does not explain the vast spectrum of asthma. There are patients who wheeze once a year; the "typical" allergic asthmatics with symptoms only during allergen exposure; "post infection" asthmatics with no personal or family history of atopy; the patients with rapidly deteriorating lung function. Asthma may well be more than one disease.
Sep 2, 2014
Dr. John Chiu
Allergy and Immunology 58 years experience
Many: Although the exact cause(s) for asthma is being debated, about 80% of asthma especially among younger people are related to allergy. Current thinking is that a viral infection is likely the trigger for its development. More recently, an abnormal epithelium (which covers the airways) is considered a major component for the development of asthma. A detailed review is not feasible .
A Verified Doctoranswered
A US doctor answeredLearn more
Asthma: Asthma is caused by reactive airways that results in excess mucous production + narrowed airways. Symptoms are usually episodic and triggered by allergies (grasses, pollen, mould) or infections. Some people get exercise-induced symptoms.
Dr. James Ferguson
Pediatrics 47 years experience
Genetics/external fr: There is ample evidence that true asthma is genetically linked to the issues of allergy & eczema & frequency is higher when one or both parents are affected. Lower respiratory tract viruses often trigger both infectious wheezing & that of true asthma early on with infectious wheezing subsiding after 3-4y. Allergies often co-exist but less than 5% of events are allergy driven alone.

Similar questions

A 41-year-old member asked:

What usually causes asthma?

2 doctor answers7 doctors weighed in
Dr. Richard Williams
Pharmacy 19 years experience
Numerous reasons: In children asthma is often linked to allergies. As we age, exercise induced asthma , occupational asthma and attacks not related to allergies play a larger part. In addition, asthma is sometimes mistaken for something else. Get checked to make sure.
Dr. Michael Zacharisen
Allergy and Immunology 34 years experience
I agree with Dr. Williams. Other common triggers of asthma include infections especially viral colds, sinus infections, cold/dry air and even GE (acid) reflux.
Jun 11, 2013
A 45-year-old member asked:

Does asthma cause dizziness ?

1 doctor answer3 doctors weighed in
Dr. Heidi Fowler
Psychiatry 26 years experience
That could occur: If you were hyperventilating or really had poor oxygen exchange. If you are experiencing an exacerbation of asthma - please obtain prompt medical care (or possibly emergent care).
A female asked about a 67-year-old female:

Can asthma meds cause asthma?

1 doctor answer2 doctors weighed in
Dr. Al Hegab
Dr. Al Hegabanswered
Allergy and Immunology 41 years experience
Unfortunately, yes: Many medicines can cause asthma as a side effect, (airway tightness rather). The most known for that are the LABAs (Long Acting Beta Agonists) meant for long term control of asthma and for airways to remain open for a longer period, but unfortunately led in some patients, especially during an asthma flare, to a paradoxical effect: airway tightening!! Hence the black box warning by the FDA
A 33-year-old member asked:

Did smoking cause my asthma?

1 doctor answer1 doctor weighed in
Dr. Richard Williams
Pharmacy 19 years experience
Possibly: Inhaling particulates like those in tobacco can cause attacks. These substances can cause inflammation which is the primary reaction in asthma followed by constriction of your lung "tubes". Of course, if you have asthma you should quit. I know it isn't easy but you must give it a try. Good luck.
A 19-year-old female asked:

Can asthma cause a fever?

1 doctor answer3 doctors weighed in
Dr. Martin Raff
Infectious Disease 57 years experience
Asthma: By itself, asthma should not create fever. You may have bronchiolitis, allergic reactions, whooping cough or other inflammatory condition exacerbating the asthma. See a pulmonary doctor.
Dr. John Chiu
Dr. John Chiu commented
Allergy and Immunology 58 years experience
If there are allergic triggers, a B/C allergist would be a better bet. Do note that viral infection is a common trigger for asthma attack and the fever is from the infection not from asthma itself.
Jan 24, 2014
Last updated Mar 28, 2022

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