Various disorders such as lupus, cancer, elevated blood homocysteine levels and inherited protein deficiencies can cause a hypercoagulable state in the blood. This makes the blood more likely to clot, and therefore thicker, explains MedicineNet. Although rare, polycythemia vera is another disorder that thickens the blood, states Johns Hopkins Medicine.
Hypercoagulable states are either acquired or inherited conditions, according to Cleveland Clinic. While inherited conditions are usually present at birth, acquired conditions result from surgery, trauma, medications or medical disorders. Types of inherited protein deficiencies that can lead to hypercoagulable states are deficiencies in antithrombin III, factor V Leiden, protein C and protein S, notes MedicineNet.
For medical conditions that cause hypercoagulable states, lupus promotes blood thickening by platelets clumping together, causing a deficiency of the natural anticoagulant protein C and inhibiting the anticoagulant antithrombin, explains the Indiana Hemophilia and Thrombosis Center. Although cancer can cause hypercoagulable states, this occurrence is not common, says MedicineNet.
In the case of polycythemia vera, the body produces an excess amount of blood cells, particularly red blood cells, which makes the blood thicker than it should be, states Johns Hopkins Medicine. Symptoms of polycythemia vera include fatigue, headache, flushed complexion and nosebleeds. Other symptoms are bruising, coughing up blood and numbness.