What condition is characterized by the body's inability to use sugar?

The condition characterized by the body's inability to use sugar effectively is diabetes. Diabetes encompasses a group of metabolic disorders where the body either does not produce enough insulin, a hormone crucial for converting sugar (glucose) into energy, or does not use insulin effectively, leading to elevated blood sugar levels.

In diabetes, there are primarily two types: Type 1 and Type 2. Type 1 diabetes occurs when the body does not produce insulin at all, while Type 2 diabetes is a condition where the body becomes resistant to insulin or does not use it effectively. The inability to manage glucose properly can lead to various health complications over time, making it a serious condition requiring careful management through diet, exercise, and medication.

In contrast, hypertension is high blood pressure, which affects the heart and blood vessels but is not directly related to sugar metabolism. Asthma is a respiratory condition characterized by difficulty breathing due to airway inflammation. Obesity, while associated with various health issues including diabetes, specifically refers to excess body weight rather than the metabolic processes related to sugar. Hence, diabetes is the correct answer as it directly pertains to the body's struggle with sugar utilization.