Ruling on informing a patient that he will die soon
Question

Is it permissible for a doctor to inform his patient that he will die soon?
Praise be to Allah.Firstly: 
The visitor or the one who is close to the patient, such as the doctor who is treating him, should raise his hopes of recovery and give him the impression that his illness is not something to worry about, and cheer him up by telling him that he will get better and be healthy and live a long life. 
Al-Bukhaari (3936) narrated that Sa‘d ibn Abi Waqqaas (may Allah be pleased with him) said: the Prophet (blessings and peace of Allah be upon him) visited me during the year of the Farewell Pilgrimage when I was so sick that I almost died… The Prophet (blessings and peace of Allah be upon him) said to him: “Perhaps you will recover and live so that some people will benefit from you and some will be harmed by you.” 
This is also indicated by what has been proven scientifically: that the patient’s psychological state helps with recovery and healing from sickness. The stronger the patient’s morale, the more likely and speedy his recovery will be. 
Secondly: 
Telling the patient about the real nature of his sickness and that this sickness may lead to his death is a matter that is subject to further discussion: 
If telling him that will not make the patient feel worse, then the basic principle is that it is permissible to tell him, whilst also reminding the patient that it is possible to recover. So for example it may be said to him: Some people were affected by this disease and recovered from it by the grace of Allah, and other such words that will give the patient hope of healing. 
But if telling him will make him feel worse, then it is better not to tell him. 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) was asked: If the doctor knows that the patient is suffering from an incurable sickness such as cancer, for example, is it permissible to tell the patient about that or should he merely hint and not say it bluntly, for fear that the patient will be psychologically affected by that? What should the doctor do if the patient asks a direct and specific question about the nature of his sickness? Should he tell him the truth no matter what the consequences, or what should he do? 
He (may Allah have mercy on him) answered:
This varies from one patient to another. Some patients are of strong character and do not care if the sickness is fatal or not. In this case he must be told the truth, because the patient may have certain relationships with his family or other people in which there are some problems that need to be corrected. So in this case he must be told, and there will be no harm in that. 
But if the patient is of weak character and there is the fear that if he is told the truth, that this is a fatal disease, he will be more adversely affected and will only focus on this sickness – and it is known that if the patient focuses on his sickness and that becomes his main concern, this exacerbates the sickness, but if he ignores it or tries to forget it, and starts behaving as if there is nothing wrong with him, then this is one of the best means of recovery. So this issue varies from one person to another. 
End quote from a lecture entitled Irshaadaat li’t-Tabeeb al-Muslim (Advice to Muslim Doctors) 
Shaykh ‘Abd al-Kareem al-Khudayr (may Allah preserve him) was asked: I heard that there was someone in my village who was sick, and when his sickness grew worse, they went to the doctor for treatment but the doctor said to the patient’s companions that he was going to die in fifteen days’ time. When this time ended, the patient died, and the people were surprised at this time frame that the doctor suggested. What is your opinion? 
He (may Allah preserve him) replied:
Perhaps this doctor said that because it is what he expected when he saw the condition of the patient and that his sickness was severe. So he said that on the basis of what he expected, not on the basis of certainty. As for being certain that someone will die at such and such a time, this is not permissible, because no one knows when he himself will die, so how can he know when someone else will die?!  
Allah, may He be exalted, says (interpretation of the meaning):
“No person knows what he will earn tomorrow, and no person knows in what land he will die. Verily, Allah is All-Knower, All-Aware (of things)”
[Luqmaan 31:34]. 
Saying that someone will die on such and such a day for certain is not permissible and comes under the heading of claiming to have knowledge of the unseen. 
But if someone says that So and so may die after a certain amount of time, or after a few days, based on his condition and sickness, and by way of expectation only, there is nothing wrong with this. But it should not be spread widely or said to the patient or his family, because this may affect the patient’s psychology or make his sickness worse, and it may also affect the psychology of his relatives. So such matters should be concealed and the patient and his family should be given the hope that he may recover, by Allah’s leave, and that his sickness will go away, and so on. End quote. 
And Allah knows best.