When your age is 60 it increases the risk of DVT.
When you sit for a long time while driving the car or flying the flight and there is no movement in your legs can increase the risk of DVT.
Other risks
The risk of DVT increases in pregnancy because it causes pressure on your legs.
The risk of DVT is also increased when you are overweight.
A clot may also be formed by some forms of cancer.
Complications
The life-threatening complication is PE. PE occurs when a blood clot blocks blood vessels in your lung. The symptoms of PE are Shortness of breath, Chest pain while coughing, and many more.
Prevention
You should avoid sitting in one place. If you travel by car you should car every one hour and move your legs.
You should stop or avoid smoking.
You should manage your weight by doing regular exercise.