When glucose (sugar) in the blood drops below the usual range, it’s called hypoglycemia. Glucose is a key energy source for the body; not getting enough of it can lead to several symptoms and problems. The most visible signs are a rapid reduction in energy and feeling weak and exhausted. Hypoglycemia affects certain individuals more often than others. Older people are more likely to develop the condition because their systems may not be able to manage glucose levels as well as younger ones. The risk is also present in people with diabetes who use insulin or other oral medicines.