Asthma: The “Hygiene Hypothesis”

CEBU, Philippines – It is one theory researchers have for what causes asthma – the “hygiene hypothesis.” The theory puts forward that today’s modern lifestyle – with its emphasis on hygiene and sanitation – has resulted in changes in the human living conditions and an overall decline in infections in early childhood.

Many young children no longer have the same types of environmental exposures and infections as children in the past had. This affects the way that young children’s immune systems develop during very early childhood, and it may increase their risk for asthma. This is especially true for children who have close family members with one or both of these conditions.

Young children who often wheeze and have respiratory infections – as well as other risk factors – are at highest risk of developing asthma that continues beyond 6 years of age. The other risk factors include having allergies, eczema (an allergic skin condition), or parents who have asthma. Most, but not all, people who have asthma have allergies.

Among children, more boys have asthma than girls. But among adults, more women have the disease than men. It’s not clear whether or how sex and sex hormones play a role in causing asthma.

Some people develop asthma because of contact with certain chemical irritants or industrial dusts in the workplace. This type of asthma is called occupational asthma.

Not all people who have asthma have these symptoms. Likewise, having these symptoms doesn’t always mean that you have asthma. The best way to diagnose asthma for certain is to use a lung function test, a medical history (including type and frequency of symptoms), and a physical exam.

The types of asthma symptoms one has, how often they occur, and how severe they are may vary over time. Sometimes the symptoms may just annoy the afflicted person. At other times, the symptoms may be troublesome enough to limit one’s daily routine.

Severe asthma symptoms can be fatal. It’s important to treat symptoms when first noticed so they don’t become severe.

With proper treatment, most people who have asthma can expect to have few, if any, symptoms either during the day or at night.

(Source: Nation, Heart, Lung and Blood Institute)