**7. Acquired coagulation disorders**

An individual can acquire coagulation disorders due to several reasons. Infections such as streptococci cause thrombosis by inactivating Protein S [124]. Chronic smoking and chronic alcoholism effect coagulation system by altering the liver functions. Environmental factors like hypoxia, drugs like aspirin, oral contraceptive pills, dietary problems like vitamin K deficiency affect the blood coagulation [12, 56–61].
