Well I don't smoke or anyting but sum of my family do and I only want to know how it hurts u!!

Cancer, emphysema, shortness of breath, so many different things. Second hand smoke is harmful as well, so it's not just themselves they are affecting, but you as well.

Google effects of smoking for more info.

There are particles and chemicals in the smoke that hurt your lung cells.
Tar is part of cigarette smoke, that may lead to lung cancer.
Many chemicals have different effects, but hardly anyone in a positive way.
Nicotine, the chemical ingredient that smokers crave for is on itself besides addictive also a cause for many illnesses, like high blood pressure. Also it can lead to cell deformation, specially in the face .

:)

The effects are felt usually long after a person starts smoking, so for young people it is too far for them to picture themselves. Even people who have quit for many years get the diseases associated with smoking anyhow.
I had one close relative die from lung cancer, one relative die from emphysema and one friend die of emphysema. Comparing the two diseases the people who died from emphysema had a more painful experience than the one from lung cancer.
Emphysema just slowly takes your breath away until you suffocate. I can't think of a worse disease related way to die.
I smoked for many years and quit long ago but I am still at risk.

Each cigarette paralyzes your cilia for 20 minutes. That's in your throat and the main reason why people who smoke, hack or cough.
~guess who paid attention in science class~ lol

Cigarettes contain over 4,000 chemicals

Carbon minoxide- car exhaust fumes and nicotine- temporarily increases your heart rate and blood pressure, and narrows small blood vessels under your skin. It slows your blood flow, reducing oxygen to your feet and hands,

Arsenic- A poison used to kill rats,

Formaldahyde- Used to preserve dead bodies,

Ammonia- floor cleaner,

Lead, tar, pesticides,

Acetylene- Used for fuel in welding torches,

Benzene- Used as an industrial solvent,

Naphythlamin- A bladder poison,

Cadmium- Used in rechargeable batteries,

Benzo (a) pyrene- A cancer promoter,

Ethyl 2-furoate- A liver poison,

As has already been mentioned, there can be many ill effects from breathing the smoke that another person is producing. If I'm around people who are smoking at all, then I can get really ill and dizzy right away.

Well, look at their skin, their teeth, their bodies, smell their hair. Listen to their laughter and their coughing. Have you ever watched them get up in the morning? Not a pretty sight.