Which of the following is an important step to diagnose hyperlipidemia?

Diagnosing hyperlipidemia primarily involves checking a patient's lipid profile through blood work. This is crucial because hyperlipidemia is characterized by elevated levels of lipids in the blood, including cholesterol and triglycerides. A lipid profile provides specific measurements that help determine whether a patient has high levels of low-density lipoprotein (LDL), high levels of triglycerides, or low levels of high-density lipoprotein (HDL). With this information, healthcare providers can assess the patient's risk for cardiovascular diseases and decide on appropriate interventions or treatment plans.

While monitoring vital signs, conducting a chest X-ray, and inquiring about family medical history may serve other diagnostic or evaluative purposes, they do not directly assess lipid levels or diagnose hyperlipidemia. Vital signs give insight into overall health but do not specifically relate to lipid levels. A chest X-ray is more useful for evaluating respiratory and cardiac conditions rather than lipid disorders. Family medical history can help identify genetic predispositions to hyperlipidemia but does not provide the immediate, quantifiable data needed for diagnosis. Thus, obtaining a lipid profile through blood work is the most direct and significant step in diagnosing hyperlipidemia.