Preparation
Total IgE measures the overall level of immunoglobulin E — the antibody class behind allergic reactions — in your blood. It is the broad first look at allergic tendency: elevated total IgE says your immune system is in allergic mode, even before individual allergens are identified.
It is most useful as a starting point for symptoms that smell like allergy but lack a pattern — year-round sneezing, itchy skin, wheezing, or eczema flares — and in supporting diagnoses like allergic asthma and atopic dermatitis. Very high values also raise certain parasitic infections for consideration.
Remember its limits: total IgE says "allergic tendency present" but not what you are allergic to — that job belongs to the allergen-specific panels (food, inhalants, drugs), which can be booked on the same draw. The test needs no fasting and works from a single home collection.
Total IgE is the quick "is allergy in play at all?" screen. If it is elevated or your symptoms clearly suggest allergy, the specific panels (inhalants, food) identify the actual triggers. Booking both together saves a draw.