The higher you are in the world, the thinner the air is. Higher altitudes mean it's more difficult to breathe and gain the oxygen your body needs.

Patients with severe sepsis, a serious type of blood stream infection, were not found to benefit from a dual antibiotic treatment. Organ failure was not found to improve compared to those taking only one drug.

Blood tests are one method that has been relied on to diagnosis tuberculosis (TB). Now the World Health Organization has warned that such blood tests can frequently be inaccurate and lead to unsuitable treatments.