What is the cause of these symptoms? Could it possibly be Intestinal parasite?

I am 5'8", 20 years old, and only 125 pounds. I have always been a small guy, but about a year and a half ago I was at around 140. Ever since I started college in september, I noticed that I've been getting more and more skinny (10 pounds of weight lost over a period of a couple months, and I noticed that I've been becoming bonier) I eat 3 full meals a day, and 2 meals on the weekends because I sleep in. I get an average of 5-6 hours of sleep, and work out a couple times a week. On the bad side though, I do smoke weed everyday [and have been for over a year] and drink once or twice a week. Could I have some kind of a disease? Is the marijuana contributing to this?
Thanks

Yep, it's the pot, you better send it to me so I can dispose of it correctly.........

Seriously...call your doctor!!!

You need to see a doctor or something cause you are sounding really sick

To lose that much weight, that fast, is never a good thing. As for it being an intestinal thing... could be... Smoking up everyday doesn't help... it is a known fact that smoking cigarettes decreases a person's appetite. I'd imagine, smoking marijuana has a smiliar effect. And seeing as how you do it everyday, your weight may be what it's targeting. The BEST advice here though, would be to see your family doctor, and keep a record of your daily meals, your weight, and just daily routines. Weigh yourself each morning when you get up, since that is the best time to weigh yourself. It isn't so much that you're skinny that you should worry about, it's the fact that the weight just keeps coming off as fast as it is.

anarexia maybe.

This could just be a stress related issue...smoking the weed please stop. Usually when starting college you put on the pounds its called the freshmen 15. But if you are concerned enough to ask total strangers make an appointment with a doc.............

well pot should make you eat...Sudden unexplained weight loss should always be investigated to find out the cause, especially if you also feel tired and shaky. Your doctor will want to check you for diabetes, overactive thyroid gland, hidden infections, and other causes of weight loss. He or she will probably arrange blood tests and a chest x-ray. Don't put off going - the sooner the cause is found, the sooner you can be treated and on the way to recovery.

Sometimes weight loss can be a sign of a depressive illness, and your doctor will want to know how you are feeling emotionally. In the meantime, try to eat a healthy diet. It can help to keep a food diary for a few days to see exactly what you are eating. Healthy between-meal-snacks such as fruit, muesli, smoked salmon sandwiches, and cheese can help you put on weight. High-carb foods such as rice, pasta and bread are also a good idea.