|Research Understanding a disease and determining a way to treat it can take up to twenty years. This research is going on all the time. Scientists will come up with a theory about what causes a disease. For example, the narrowing of airways that occurs during an asthma attack.
Target They will then target a part of the biological process that causes the problem. This might be a missing protein, a lack of a hormone or a defective gene. In the case of asthma, scientists knew that adrenalin acted as a bronchodilator and, although not suitable itself, they reasoned that a similar substance might work.
Discovery They will then look for or design suitable compounds which might prevent, treat or cure the disease. Sometimes these compounds are based on substances already produced in the body, or are developed from plant sources. Computers are very important in medical research because they are used to help design new compounds and to select those which look most promising.
It can take several years to get a group of likely compounds, and up to 10 000 possible new chemicals might be investigated.