Numb Waist to Right Leg [behind Perspective]

Hello,

i am very worried about my father. He is turning 48 years old within two months and he is experiencing constant numbness in his waist and his right leg [behind perspective]. He said to me that his right leg "feels cold, and sometimes paralyzed" and in extreme occasions he used his left leg while driving (normally he uses his right leg to control the acceleration and the brake pedal). Also, he sometimes limps.

Here are his problems:
- he is smoking for 39 - 40 years now
- he is tad bit over weight (he is 5'11 and weighs about 230lbs)
- he does not exercise, but when he does, he is on his bed (those rubber stretching things)
- he eats fried and greasy foods (my mother is a bit used to this, I am trying to make her change her cooking habits)

i tried telling him to stop smoking, but he always finds scapegoats and changes the topic. He can't accept the truth when it comes to smoking (one of the symptoms for long term smokers).

I also feel that our family doctor is not helping much. It's either me or my dad not following her orders. Since, my dad went to the doctor and my doctor said that he must stop eating greasy and fried foods, stop smoking (obvious), and recently told my father to lose weight (this is when my father encountered the numbness of his waist to right leg for the first time).

He is currently taking pills for his peptic ulcer and others pills that I don't know. But perscribed to him.

I don't know what is going on!

Can you please help my father, I love him very much. He is a very strong and ambitious man and I don't nothing happening to him.

Please help me.

Thank you.