How long do cigarettes show up in blood and urine tests?

Dear tmacd, 

According to the American Lung Association (as quoted in an article
about insurance tests), "nicotine disappears from your blood stream
and your urine within 72 hours after smoking your last cigarette."
(SOURCE: "Can You Hide Smoking From Life Insurance Companies?",
Insurance.com, <http://www.insurance.com/Article.aspx/artid/245>).

However, according to  Julie Possner, a paramedical examiner with Exam
& Profile Services in Wisconsin,  "Cigarettes [nicotine] will show up
many days or even weeks after use in somebody's urine. It will
probably still show up if someone has refrained from smoking for a
short time prior to the exam." (SOURCE: "The Lowdown on Life Insurance
Medical Exams", Yahoo! Insure.com,
<http://insurance.yahoo.com/lh/medicalexam.in.html>).

I hope this answers your question. Please contact me if you need any
clarification on this answer before you rate it. My search strategy
was to search for the following keywords:
"show up" blood urine tests cigarettes nicotine

Lets say the last time I smoked a cigarette is July 31.  Any idea when
I sould wait until I go for a Life Insurance Test???  Also I really
only started smoking in about March for real! Any Ideas?

When you hide smoking from an underwriter and they find out about it,
they may become suspicious about the honesty or withholding of other
information on your application. E.g. you are also on blood pressure
medication; will the underwrtier now believe your statement that
you've not had a b/p reading over 145/90 in the past year? Once
inconsistencies are noted (and they can be found by comparing labs
results, the application, phone interview, and doctor's notes), you
lose the benefit of the doubt that might have resulted in your getting
a better rating.

There is one company that will consider Nonsmoker rates for
occassional cigarette smokers. See www.outlooklife.com for more
information.