How to know if someone is using marijuana?

Question

what specific test are available and can they be masked

Answer 1

objectively, people using marijuana as smoke usually gets yellow discoloration in the fingers,

attitudes will greatly changed, sunkenn eyeballs without any illness that would cause that one.Euphoria ( state of being so happy) without any reason is also a sign that a person is using marijuana.

in the laboratories:

this will be seen in the Blood test,

Urine, saliva and even breath test for persons still under the domination of marijuana.

-=jess=-

Answer 2

Blood tests or saliva & hair tests.  No they cannot be masked xx

Answer 3

All the test mentioned are sure fire but also MJ stays in your system quite a while especially in your hair follicles.  Only until the hair actually falls out it will be gone....

Answer 4

Here is what the police do.

Answer 5

Urine, blood, saliva and/or hair test.  I think they have at least one of these over the counter...