As sentient beings we all are vulnerable to sickness, old age and death. These are the instances in which everybody suffers a lot. However, the whole weight of suffering is not determined by those actual realities but by our attitude or the way we take them. For example, a miner sickness can bring a severe suffering to somebody while a severe sickness might bring an average level of suffering to another. In Buddhism we try to develop a self realization on those issues. When we closely observe, we can realize that main cause of suffering is our self centered thinking and craving. When we can do some change in our habitual way of thinking and emotional attachments, we can maintain peace even amidst sickness, old age and death. The Buddha says that when an ordinary person is experiencing a sickness, he is like being shot by two arrows. The first arrow is actual physical pain he is going through. The second arrow is our mental resentment or agony about being sick. According to the Buddha, the second arrow is more severe than the first one. We should develop the wisdom to not get the second arrow when we are sick. There are some other practices we can do in facing a sickness. Whenever we are experiencing a pain or going through a sickness, it gives us an important opportunity to realize the suffering of others. We do not suffer alone. There are many beings going through the same or severe level of suffering. Therefore, having a sickness is a good chance to develop compassion. Because we know exactly how it feels like when others are sick. With that knowledge we can develop a great compassion in our heart. Based on that deep compassion we can do meditation on Loving Kindness (metta) by spreading our good wishes for all living beings in a gradual way. Sickness also gives us a chance to be aware of our body. Then we can do the meditation called Contemplation of the Body.
We can begin to feel the every movement of the body and be aware of those movement and sensations as they feel. We can also do a mental body scan which is to paying a close attention to each part of our body gradually from head to toe and relaxing each part with a strong wish. If we can mentally go through whole body everyday wishing good health and recovery for each part of the body, that exercise will speed up the recovery process. If we are attending to a sick person, we also can sit closely to that person and send our selfless good wishes for that person with some touch for a particular period of time in each day. Even physical pain can be our object of meditation. We closely observe the pain (how it arises, how it exists, whether it is continuous or rising and falling etc), we can overcome our mental resentment about it. It reduces the gravity of the pain. It develops an attitude of acceptance which helps us greatly to heal ourselves.