How does surgery itself cure diabetes, hypertension, etc?

How does just having weight loss surgery cure you of things like high blood pressure, diabetes, etc? I hear some people say that when they're sent home from the hospital, they are considered cured of these things and no longer have to take medication. How does the surgery itself immediately fix these things?

It is not the surgery itself that assists in getting WLS patients off medications or "cured" from disease. The weight loss/ food intake (lifestyle change) is what does it. Immediately upon having surgery your food intake has changed. Also, for those doing a liquid pre-op diet, the food intake has changed as well. I know in the week before surgery I did the protein liquid diet and lost 10 pounds. Additional changes that occur is the absorption or should I say malabsorption which decreases the need for things like insulin doses. I believe most patients still require some medications upon discharge but as time goes on and the weight comes off they can be "cured" of disease or medication requirements can be lessened.
If the WLS patient continues to eat the wrong foods, or gains the weight back they may have to be placed on medications again and disease can return.

These issues "go into remission" as you lose wt.  Once a diabetic, always a diabetic-- but surgery makes the daily issues go away. Gain appreciable wt again, you it will return. I went off of my BP pills after my RNY. But several months later, I developed dizzy spells. After a bunch of tests, my doctors decided I needed a pacemaker to control my lower bp rate. And after the implant, my cardio doc had me go back onto the bp meds again.  DAVE

There is SOME evidence that just having the surgery -- separate from losing any weight -- does "cure" diabetes.  There is enough evidence that there are doctors who are encouraging only mildly overweight diabetic patients to have RNY.  Even Dr Oz did a show on it. There are no long term studies on whether the diabetes stays in remission (most doctors say that it is really never "cured"), though, especially for people who weren't obese in the first place.  There are a couple of theories that I have read about, but (unless they have discovered something fairly recently) no one knows exactly why RNY has such an immediate effect on diabetes.

Lora

I don't know how it happens, but I was sent home from the hospital without needing to be on my diabetes and blood pressure medications.

I check my blood sugar & blood pressure regularly, but both are ideal. Even right when I got home from surgery.

I love this surgery!

I never went back on my diabetes medicine after my surgery 4.5 years ago - my understanding is it has something to do with hormones, the pancrease and the duodenum (that really cleared things up, huh?)  By the way, my PCP considers me no longer diabetic, not in remission.  I really don't care what you call it, I am just happy to be off the meds and having normal blood sugar levels and A1C results.  I think they are trying to develop this same type surgery for diabetics that do not need to lose weight - that would be great.

I did have to go back on BP meds after 3.5 years and my only fluctuates by about 5 pounds - doctor told met this could be hereditary. 

My other problems were resolved by the weight loss itself, in my opinion.

Not sure but I was told because it bypasses the duadeum? You are in remission, once a diabetic always a diabetic. I still have diabetic neuropathy associated with my years of diabetes it didn't go away. Weight loss does not always have an effect on diabetes. I know several people rail thin that are diabetics.