I seek refuge with Allah and with His Power from the evil that afflicts me and that which I apprehend
Abu 'Abdullah ibn Abul-'as (May Allah be pleased with him) reported:
I complained to the Messenger of Allah ( may the peace and blessings of Allah be upon him ) about a pain I had in my body. The Messenger of Allah ( may the peace and blessings of Allah be upon him ) said, "Place your hand where you feel pain and say: 'Bismillah (in the Name of Allah)' three times; and then repeat seven times: 'A'udhu bi'izzatillahi wa qudratihi min sharri ma ajidu wa 'uhadhiru ( I seek refuge in Allah and in His Power from the evil that afflicts me and that which I apprehend ).
[Muslim]
This Hadith is a proof that a person can complain - without showing discontentment with the decree of Allah – to his beloved ones, so that they would help him, or for the righteous, so that he may find the blessing of their invocations. Most likely they will supplicate Allah for him and advise him to follow the Prophetic traditions. He may reach all of these blessings because of his complaint.
The companions of Prophet ( may the peace and blessings of Allah be upon him ) used to complain to him. Yet, he did not blame them for that, because he knows that they do not complain to him out of discontentment with the decree of Allah. Rather, they want him to teach them the remedy of their physical and spiritual diseases. The Prophetic love, mercy, leniency made him more merciful to them than themselves.
There is a secret in repeating this supplication seven times but we have to follow and submit to the Prophetic Sunnah..
How effective is the supplication in terms of healing, it is one of the greatest reasons for the satisfaction, but we should not neglect the medication of the known medicines, and ask Allah to make the medication useful with his permission.