Although diving is a very calm activity that does not require a high fitness level, one must always be aware that the water is not a safe area to be in. One can encounter marine creatures that contain poisonous spikes. Aside from such forms of marine life, there are some medical conditions that one must watch out for.

Inner ear barotrauma, for example, is a condition you may encounter if you have some problems with equalizing. This is accompanied by dizziness and loss of hearing. Another medical condition that you should be aware of is pulmonary barotrauma which can happen because of improper breathing while ascending to the surface. Symptoms of this are chest pains, shortness of breath and hoarseness. You can also acquire arterial gas embolism if your ascent is too fast. Symptoms of these are numbness or tingling of the skin. Weakness or paralysis may follow so you'd better head to the nearest hospital if you end up with any of these symptoms. You should also watch out for decompression sickness which can cause the dysfunction of the spinal cord, brain and lungs.

Remember that all of these conditions are very serious and require immediate medical attention. You should also make sure that you listen to your diving instructor or guide to avoid such problems.