Some so many people have not had a blood test in years. The idea of not knowing what is happening inside your body is like driving a car for years and never checking under the bonnet to see if your washer bottle needs water or your engine oil is low. No attention to your vehicle and your engine blows up, so no attention to your body, and you may get sick.
N90 strongly advises that you have your blood tests done. How regular will depend on what your health practitioner advises based on your current health status and if there is any previous history of a disease. The results can guide your health practitioner on the correct protocols to get you back into optimal health.