Runny noses, congestion, sneezing, and mild coughing are other similar symptoms to the common cold that may present with a whooping cough in adults. Usually, severe coughing begins after a week or two. It can last up to 10 weeks and cause pneumonia and other complications. Pneumonia can be very serious and even deadly, but most people respond well to treatment. A weakened immune system, an older adult, a very young child, or someone with diabetes or cirrhosis are more likely to have complications from ensuing pneumonia. Complications of pneumonia can include a severe form of respiratory failure called acute respiratory distress syndrome (ARDS). A lung abscess is a collection of pus inside or around a lung. Surgery may be required to drain them. A breathing machine or ventilator is required in the event of respiratory failure. Sepsis can occur when the infection enters the bloodstream. Organ failure may result. Other medical conditions may have similar symptoms to whooping cough. Diagnosis should always be sought from your health care provider.