And how can it be treated?

Symptoms of lung failure are:
1.)Cough-is a sudden, explosive exhalation of air; the function of a cough is to clear material from the airways.
2.)Dyspnea-(shortness of breath) is the unpleasant sensation of difficulty in breathing.
3.)Chest pain-Chest pain may be described as sharp (possibly knife-like), dull, burning, or squeezing; it may be located in a specific spot on the chest (such as the chest wall) or may be difficult to locate, often feeling like a deep ache. the pain may be constant or intermittent, lasting seconds, minutes, or longer. it may be worsened by breathing, changes in body position, exertion, eating, or other factors.
4.)Wheezing-is a whistling, musical sound during breathing resulting from partially obstructed airways.
5.)Stridor-is a gasping sound during inhalation resulting from a partial blockage of the throat (pharynx), voice box (larynx), or windpipe (trachea).
6.)Hemoptysis-is the coughing up of blood from the respiratory system.
7.)Cyanosis-is a bluish discoloration of the skin resulting from an inadequate amount of oxygen in the blood.
8.)Clubbing is an enlargement of the tips of the fingers or toes and a change in the angle where the nails emerge.

Emergency treatment follows the principles of cardiopulmonary resuscitation. Treatment of the underlying cause is required. Endotracheal intubation and mechanical ventilation may be required. Respiratory stimulants such as doxapram may be used, and if the respiratory failure resulted from an overdose of sedative drugs such as opioids or benzodiazepines, then the appropriate antidote such as naloxone or flumazenil will be given.

If ever you think you have this. please consult your doctor right away and hope I helped.