The mind has an influence on the body, and vice versa. The two work together; neither side can be ignored. Taking medicine is not wrong in principle; what is wrong is to attend only to the body and ignore the mind. If there is a need for medicine, then take it, but be careful that you do not let it be a support and become dependent.
When the mind is kept free from tension and worry, sleep comes naturally. Or, even if you cannot sleep, there will be such peace and calm that you will still feel refreshed.
Learn to be your own spiritual doctor. Whatever the nature of an illness – heart problems, cancer, or simply intense pain – it is through the power of remembrance of God that illness can be overcome. This will also protect you from the negative things your friends and even doctors might say about your health. Sometimes, even just hearing about another’s illness makes people worry about getting it themselves.
If there is something wrong with you, worrying about it and spreading your worry to others will only aggravate your ill health. So even if the body is sick, learn how to let the mind simply remain in the remembrance of God. If there is even a trace of worry, no cure can be effective.