O22: Venous complications and haemorrhoids in pregnancy

O22.3: Deep phlebothrombosis in pregnancy

Veins are blood vessels that transport the blood back to the heart. A distinction is drawn between surface veins beneath the skin and deeper-lying veins in the body’s tissue.

When the blood in deeper-lying veins flows more slowly than normal, the blood in those veins can get held up. When blood inside a vein gets held up, a blood clot can form and the vein can get blocked. The affected part of the body can then swell up and be painful. However, the blood clot can also get into other organs via the bloodstream and damage them as a result.