Slender man सवालों I need answered.

Slender: A dare maybe?
Slender Sanatorium: Magic?
Hospice: Trying to change things up a bit>
Elementary: Probably night
Mansion: Extreme paranoia, nausea, blood noses, coughing, amnesia. These are usually the symptoms seen in the vlogs.
Claustrophobia: Probably can't get into the bushes, and even if आप could, Slenderman would find आप anyway.

Slender; आप saw a piece of कैन्डी on the other side.

Slender Sanatorium;There IS a door, Slender's just trying to make sure आप don't find it. (or it's invisible :p)

Hospice;They're trying to make आप feel hopeless.

Elementary;You're stuck in a time freeze, so who knows.

Mansion;Nausea, hearing your दिल pounding, riniging in the ears
Claustrophobia;The bushes are actually man-eating monsters, and HOPEFULLY आप know a lot better than to go in those things!

I can answer the "Slender Sickness" question. Slender Sickness came from the लोकप्रिय Slenderman ARG Marble Hornets. It consisted of coughing and wheezing. It mostly happened to people who were near him and Proxies. Most other ARG's try to copy this या lack it. In Marble Hornets, the apparent cure for it is strange, rare, unnamed pills in unmarked bottles. Hope this helped आप understand Slender Sickness a little more.