There are two main types of asthma. The first is allergic asthma, and 9 out of 10 asthma sufferers fall into this group. This means that you or someone in your family is allergic to one or more common allergens.

The second type is non allergic asthma, or intrinsic asthma, of which doctors do not really know the causes because there is no history of the disease in your family, and you do not seem to be allergic to anything.

In either case your asthma may be mild, moderate or severe, and if it has been going on a long time it is chronic. Then there is brittle asthma, which is very rare, where you may have a sudden attack, usually brought on by an allergy, which comes out of the blue and is difficult to control. Finally, there is night time or nocturnal asthma.

Is this has anything to do with hay fever? Every year during the flowering seasons hay fever affects tens of millions of people. At the height of the hay fever season up to a third of us will show a positive reaction to a skin test using extracts of pollen.

Hay fever or to give it its more accurate name, seasonal allergic rhinitis, is not caused by hay, nor does it cause a fever. It is an allergy to airborne pollen from trees, grasses, plants and mould spores.

Some people are allergic to just one or two types of pollen, others are sensitive to several. In the southern hemisphere, grasses and trees are the major causes of hay fever. Allergic rhinitis generally is characterized by sneezing and a runny or blocked nose, often accompanied by itchy, watery eyes.

Sufferers may feel unattractive, grumpy, tired, run down and unable to concentrate. It prevents many from enjoying a good meal, and the constant sniffling and sneezing take the enjoyment out of kissing. It may even put the dampers on sex.

You can develop hay fever at any age, but it normally makes its appearance between 8 and 20, and rarely after 40. Men are more likely to have hay fever than women and contrary to popular belief, it seems to more common in cities and towns than the countryside.

Hay fever rates have increased fourfold over the past 20 years, despite falling pollen counts associated with the reduction of grassland. Scientist says that vehicle exhaust pollution is sensitizing the airways of hay fever sufferers, making then more prone to allergies.

Proteins on the pollen grains are washed off and stick to particles in the polluted air which, because they are so small, are breathed deeply into the lungs.