What is the primary difference between Type-A and Type-B personalities?

Presence or absence of Type-A traits

People characterised by Type-A personality seem to possess high motivation, lack patience, feel short of time, be in a great hurry, and feel like being always burdened with work. Such people find it difficult to slow down and relax. People with Type-A personality are more susceptible to problems like hypertension and coronary heart disease (CHD). The risk of developing CHD with Type-A personality is sometimes even greater than the risks caused by high blood pressure, high cholesterol levels, or smoking. Opposite to this is the Type-B personality, which can be understood as the absence of Type-A traits.