Blood in cough is due to pulmonary tuberculosis infection which will stop after treatment. Normally uncontrolled diabetes patient has raised blood sugar levels causing blood to get more viscous (thicker) . Viscous blood can easily block small arteries and arterioles. Most commonly cerbral arteries and coronary arteries are smallest in diameter and more prone to get blocked. If cerebral arteries blocked patient may get paralysed. Insulin has anti inflamatory properties and choice of treatment in TB patient.