Complete Blood Count (CBC): What You Need to Know About This Common Blood Test

A complete blood count (CBC) is a common laboratory test that measures the different cells in your blood, including red blood cells, white blood cells, and platelets, to help evaluate your overall health.

The Aspergillus fumigatus antibody test is a blood test that detects whether your immune system has produced specific antibodies against Aspergillus fumigatus, a type of mold commonly found in soil, decaying vegetation, and indoor environments. This test helps healthcare providers determine if you have been exposed to this fungus and whether your body has mounted an immune response.

Your doctor may order this test as part of a routine checkup, to help find the cause of symptoms such as fatigue, weakness, fever, or unusual bruising, or to monitor a condition like anemia or an infection you already have.

Your doctor may order this test if you have symptoms of a respiratory infection that hasn't responded to standard treatments, especially if you have a weakened immune system due to conditions such as HIV/AIDS, cancer, organ transplantation, or long-term steroid use. Symptoms may include fever, cough, shortness of breath, chest pain, and fatigue. The test is also used to monitor patients at high risk for fungal infections.

The test is performed by drawing a small sample of blood, usually from a vein in your arm. A healthcare provider will clean the site, place a tight band around your arm, insert a thin needle, and collect the blood into a tube.

A healthcare professional will draw a small blood sample from a vein in your arm. The sample is then sent to a laboratory where it is analyzed for the presence of IgG and IgM antibodies against Aspergillus fumigatus. IgM antibodies typically appear first during an active infection, while IgG antibodies indicate either current or past exposure. The test results are usually available within a few days.

Your results show whether your blood cell counts fall within normal ranges. Abnormal levels may suggest conditions such as anemia, infection, inflammation, or clotting problems, and your doctor will interpret them together with your symptoms and medical history.

Results are typically reported as positive or negative. A positive result means antibodies were detected, suggesting you have or previously had an Aspergillus fumigatus infection. A negative result means no antibodies were detected, which could indicate no infection, very early infection (before antibodies developed), or a suppressed immune system that cannot produce detectable antibodies. Your doctor will interpret these results in combination with your symptoms, imaging studies, and other laboratory tests.

This test is very safe. You may feel a brief sting when the needle goes in, and the puncture site may be slightly sore or bruised for a day or two. Serious complications are rare, and you can usually return to normal activities right away.

The risks associated with this test are minimal and include slight pain or bruising at the injection site, lightheadedness, and in rare cases, infection. These risks are similar to those of any routine blood draw.