Hereditary or acquired susceptibility to occlusion does not increase the risk of developing a serious coronavirus infection.

However, a coronavirus infection involves a greater risk of venous thrombosis than other respiratory infections, as the coronavirus infection activates the coagulation system. In particular, this should be taken into account when a person already has an increased risk of venous thrombosis.

In addition to the actual susceptibility to occlusion, the risk of occlusion is also increased for people who

• have diabetes, cancer or vascular diseases such as previous cases of upper or lower limb thrombosis or pulmonary embolism
• have a severe inflammatory disease (e.g. rheumatism, inflammatory bowel diseases)
• are aged over 60
• are overweight
• have recently undergone a large operation
• have an orthopaedic cast
• are pregnant or have just given birth
• are using contraceptive tablets and hormone replacement therapy
• are dehydrated or have been immobile for more than three days

If a person has previously had a venous thrombosis or pulmonary embolism in an upper or lower limb, or if he or she has more than one of the other factors that increase the risk of thrombosis and becomes infected with a feverish coronavirus infection, he or she should contact their doctor. The doctor will individually assess whether the person needs anti-thrombosis medication because of the infection.

During a coronavirus infection, the risk of occlusions can be reduced by

• keeping well hydrated
• changing one’s position
• moving one's lower limbs
• being upright when possible
• moving around indoors
• using support socks when resting in bed, if these are available and have been used at other times to prevent occlusions.