Does cupping help with knee pain that affects an elderly man?

The Shaykh : By the way, you see that I have pain here above the knee.
The student: Yes.

The Shaykh : You see, cupping is beneficial.
The student : It is very beneficial for me.

The Shaykh : You say to be patient, but that is comparing two different things. You are young and I am an old man.
The student: Yes.

The Shaykh : So I wanted to say, you see, it is beneficial, and I am a very old man.
The student : It is beneficial, but with conditions.

The Shaykh : Yes.
The student : First, that you do not have diabetes, and second, that there is no weakness in the blood. And if Allah wills, if these conditions are met—if the diabetes is absent and the blood weakness is absent, meaning it is not present—then if Allah wills, it is beneficial.

The Shaykh : Yes, in the past, how did they know if someone had diabetes or weak blood?
The student : Frankly, I do not know about the past.

The Shaykh : And how did you know now that this is a condition for cupping?
The student : Now, from science, I mean, when they talk about medical technology, they say that if a person has diabetes and gets a wound, the wound keeps bleeding and it can lead to danger. Likewise, if a person has weak blood, meaning he loses any of the blood in his body, it also leads to fatigue in the body itself. So, as a precaution regarding the second issue, weak blood, as a precaution and not as a certainty, we do not perform cupping for someone with weak blood.

The Shaykh : Okay, you are now a cupper. Can you not tell from your cupping who has weak blood or who is strong like me?
The student : Yes, you may.

The Shaykh : Then.
The student : Of course, this is possible. It may remain a conjecture for me, but I know.

The Shaykh : ... Hehe hehe.
The student : I mean, two cases happened to me.

The Shaykh : ... .
The student : One person came, and another.

The Shaykh : Answer the question.
The student: Yes.

The Shaykh : Do you mean a strong conjecture or a weak one?
The student : No, a strong conjecture, if Allah wills.

The Shaykh : A strong conjecture, okay.
The student: Yes.

The Shaykh : A strong conjecture, okay, how is that?
The student : Two people came to me.

The Shaykh : No, no, leave me alone.
The student : It is practical, because...

The Shaykh : Leave me alone, stories.
The student: Yes.

The Shaykh : I am telling you, how? Give me an answer briefly?
The student : It is a lot, I mean, when a lot of blood comes out from a person, he knows that his blood is strong and apparent. And sometimes another person is cupped in the same place, but only a very small amount of blood comes out. And some people say that you can know that a person has weak blood from his eyes.

The Shaykh : Okay, I think that cupping draws out the bad blood.
The student: Yes.

The Shaykh : If that is the case, then you will know if his blood is light or not, because if the black, bad blood comes out, then his blood is strong. But if the clear blood comes out, then that is what you mean by his blood being sick.
The student : May Allah reward you with good.

The Shaykh : And beware of that.
The student: Hehehe.
Another student: ... And may Allah reward you.

The Shaykh : And may He reward you.