CBC

Do I need to fast before a CBC?

No, fasting is not required for a standard CBC. You can eat and drink normally before the test unless your doctor has also ordered a fasting test like blood glucose alongside it.

How long does it take to get CBC results?

Most labs process a CBC within a few hours, and same-day results are common. Emergency departments can often get results within 30–60 minutes.

What does a low platelet count on a CBC mean?

A low platelet count, called thrombocytopenia, can result from a viral infection, certain medications, an autoimmune condition, or a bone marrow problem. Your doctor will usually recommend a repeat test or additional workup to identify the cause.

Can a CBC detect cancer?

A CBC alone cannot diagnose cancer, but unusual patterns — such as a very high or very low white cell count, or abnormal-looking cells noted by the lab — can prompt your doctor to investigate further with additional tests like a peripheral blood smear or bone marrow biopsy.