When a pilot experiences a medical problem that is less serious and obvious, decision on regarding the fitness to fly is not always straightforward. Decision on whether to fly with a minor illness can often be a difficult decision. If in doubt always contact an aviation medical doctor for advice. Even a minor illness can seriously affect the performance of the pilot to maintain safe flight. The following paragraph provide a brief explanation on some of the common minor illnesses faced by pilots
Most minor illness do not require any medication or drugs. It can be simply overcome by such measures as increasing intake of fluids and adequate rest. Medication from the local pharmacy to treat minor illness for the pilot should be avoided, as the medication sometimes contains drugs that will have adverse effects on the body, particularly to the brain. During any time there is a doubt about the pilots ability to fly safety seek advice from an aviation medical examiner or else don't fly at all.
Some common Minor Illnesses
The following paragraphs provide a brief explanation only. If in doubt consult your aviation medical doctor before flying.
A cough is an infection to the throat or lungs. Coughing is an action by the body it takes to get clear substances that are irritating to the air passages. There a different types coughs with different medication for each type of cough. However, majority require no medication, other than drinking plenty of water, rest and avoiding irritants such as smoking. Pilots should see a doctor if the cough worsens, a sore throat develops, or lasts more than a couple of days. Note that germs can spread easily when a person doesn’t cover up their coughs, so be caution of the people are sick around you. Overall a cough should not usually prevent a pilot to fly unless it's very uncontrollable and other symptoms develop with it such as a fever, headache etc.  
A viral infection of bacteria that accompanied by other symptoms such as sniffles and coughing. Usually sore throat will get better on their own but treatment can be a simple pain relief or lozenges to lubricate and soothe irritated tissues of the throat. Usually there is no need to visit a doctor unless symptoms are still present after a while and the throat becomes sorer and red. It will not limit the pilot's ability to fly, unless other symptoms are associated with it. 
Cold and Sinusitis
The “common cold” is a viral disease of the upper respiratory tract which affects primarily the nose. Symptoms include a runny nose, sore throat and fever, which usually last three to five days. There is no proven cure for the common cold yet, but the symptoms can be relieved by medication. Washing hands regularly is recommended to prevent the spread of the common cold germs. Colds have two main concerns with pilots. Firstly, it slows down reaction time and decision-making skills especially in an emergency. Secondly, a cold will congest and may block the sinuses, nose and ears. If the sinuses becomes block, during a climb or descend the pilot will be unable to “equalize” the pressure inside and a pain can be experience from the trapped air. With the block ears, air can expand and escape the eustachian tube during the climb, however it cannot escape during a descend. This can lead to the pilot to experience severe pain, dizziness and possibly rupture of the eardrum. If the eardrum ruptures, the pilot will experience hearing problems and possibly unfit to fly for a period of time. Pilots with a heavy cold should therefore be advised not to fly. However, if the pilot is recovery from a cold or has a light cold a technique used to clear the ears called “Valsalva manoeuvre” can be used. 
|Video embedded from [http://www.youtube.com/watch?v=NYnnAH2iInc] on 29 September 2012|
Pilots who experience the flu are attack by an influenza virus and should be advised not to fly. Relatively severe symptoms are associated include coughing, fever, chills, aches and sore throat. Pilot’s should see a doctor for medication and drink plenty of water with lots of rest. They should also be in a separated room, which is well ventilated and away from other people as the flu can be spread through the air and from touched contaminated surfaces. 
The most common cause of diarrhoea is food poisoning and lasts between one to three days. Eating as little as possible, but increasing fluid intake is the best way to combat diarrhoea until symptoms have subsided. Pilots will experience stomach cramps and severe dehydration and if symptoms get worse pilots are advise not fly and seek medical advice until settle back to normal routine. 
IMSAFE is a checklist that can be used by pilots to assist whether they are fit to fly. They should treat every element of the checklist seriously before commencing flight.
|http://ehfc.net/trainingandsafety.html on 29 September 2012|
Want to know more?
- This offers detailed information about Fitness to Fly for Pilots
- Ewing, R. (2003). Aviation Medicine and Other Human Factors for Pilots- 5th Edition. Old Sausage Publishers Limited.
- YouTube (2012). Ear Equalization Techniques - Valsalva Maneuver - SingHealth Healthy Living Videos. Retrieved September 29, 2012 from http://www.youtube.com/watch?v=NYnnAH2iInc
- Coughs Retrieved September 29, 2012 from http://www.emedicinehealth.com/coughs/article_em.htm
- Air-3.0 Medical Information Retrieved September 29, 2012, from http://www.tc.gc.ca/eng/civilaviation/publications/tp14371-air-3-0-463.htm