By taking marijuana a person becomes weak both physically and mentally. For a person to get back to normal state, at least a time period of one month is needed. If the person uses marijuana heavily then it will last even longer, increasing the time needed by the person to get cured.

Smoking marijuana affects blood flow of the body. When compared to the persons, who will not smoke marijuana, the blood flow will be higher in the brain for the people who will smoke. In some cases, there will be a huge resistance for the blood flow which means the blood vessels which are in the brain are limiting oxygen in reaching the tissue effectively.

Depending upon the frequency of the use, the blood test can detect the presence of the marijuana. Blood drug test for detecting marijuana will exactly give the intoxication rates.

Here the person who has taken marijuana will be examined with the sample of blood which is being collected from the artery or vein of the infected person.
Blood test is an expensive one and most of the companies and the institutions will not use this test because of its expensiveness. They are done for the persons who are driving to prevent accidents. But the result of the blood drug tests will be more exact when compared with the urinalysis. THC tetrahydrocannabinol will be passing through the blood streams initially and finally passes into the brain.

For a frequent user of marijuana, the blood drug test detection periods will be up to two weeks and for the infrequent users, the blood detection periods will be up to three days. Which means the marijuana will long last for about three days, if the person is not a frequent user.