Natural cures for blood poisoning
It is not clear exactly what you mean when you say that a line has gone up to your sister's armpit. Is there some kind of mark on her skin in this area, or has she been pierced by some object that she thinks could be infected?
Blood poisoning, medically known as sepsis, is an extremely serious condition, and if your sister is experiencing symptoms that indicate sepsis, she should visit a doctor immediately. There is no "natural" treatment or home remedy for sepsis. Antibiotics are indispensable, and along with them the patient may need to be drained of infected fluid (which then also necessitates fluid replacement), and also be given other treatments depending on which organs have been affected.
Sepsis is basically a condition in which bacteria or other pathogens spread across the blood and tissue themselves. The symptoms of sepsis or blood poisoning include fever and inflammation of the whole body. Since you have not mentioned these or any other symptoms in your question, it is unlikely that your sister is suffering from sepsis. However, if there is some recently developed and unusual mark on her skin, she should still visit your family doctor and find out what the mark is.
answered by G R