Lung function examinations are done to determine the reasons behind problems such as shortness of breath, cough, fatigue after effort etc. and set the best course of treatment. The examination can also help diagnose asthma and COPD, follow the progression of the treatment and determine its effectiveness. 
The lab also treats patients about to undergo surgery to evaluate their ability to withstand general anesthesia. 

Examinations performed at the lab
Spirometry
This examination helps diagnose obstructive diseases of the airways such as asthma or COPD, and risk factors for various lung diseases. The examination takes 5-10 minutes and has no risks. 
The examination is recommended for patients suffering from difficulties in breathing during effort or rest, extended cough and excessive phlegm, and smokers, with or without respiratory complaints. 
The patient needs to actively cooperate with the examination and obey the technician's instructions otherwise the diagnosis may be flawed. 

During the examination you'll be asked to take a deep breath and exhale into the spirometer for several seconds. This is done several times. 

The examination measures the total lung capacity (TLC) - the maximum amount of air that can be inhaled into the lungs. Diminished volumes indicate a restrictive disease, increased volumes indicated an obstructive disease (the air goes in but has difficulty going out - hyper-inhalation). The diagnosis of a combined disease requires a spirometry exam and a lung volume exam. 
Spirometry can indicate obstructive diseases that interfere with airflow like asthma and emphysema, or restrictive diseases where the overall lung volume is reduced (like fibrosis), there is scarring in the lung or scoliosis. The numeric value of the exam's results indicates the severity of the disease. 

Diffusion capacity test
This examination measures the penetration ability of gases into the lungs and their turnover in the lungs. 
A low result with a restrictive disease indicates scarring in the lung (in such cases the oxygen has difficulty reaching the blood stream, therefore the diffusion will be low). If the diffusion capacity is within normal parameters but the overall volume capacity is reduced, this may indicate a disease of the respiratory muscles or weakness in the chest wall. An obstructive disease with low diffusion indicates emphysema, which is characterized by a reduced amount of blood vessels in the lung, which in turn interrupts the oxygen's penetration. 

Oximetry test
This examination measures saturation in the arteries. The examination can be performed at rest or effort in patients that experience limitations during effort. The examination can also help evaluate the levels of oxygen in patients on oxygen. 

Metacolin challenge text
This examination helps diagnose asthma. It is done when there's suspicion of asthma but the lung functions are normal, or when the symptoms are not typical or non-specific. 
During the examination the patient inhales gradually increasing concentrations of metacolin. This substance can cause the muscles around the airways to contract and the airways to narrow. A spirometry test is done before the metacolin challenge and the lung volume is measured at every metacolin concentration. 

Asthma effort challenge
An effort test is meant to identify pulmonary symptoms caused by effort, i.e. exercise-induced asthma (EIA). The patient is asked to perform a few minutes of cardio on a running track or on an exercise bicycle. A spirometry test is done before and after the cardio. 
This test is important in determining the treatment plan for patients with asthma symptoms following exercise and for physically active patients. 

Heart-lung stress test
The test is used to diagnose specific cases where it is unclear if the reason for the shortness of breath is cardio-vascular or pulmonary. The test also allows to evaluate athletes' fitness, disability and effort ability in people that suffered an injury to their thorax, risk evaluation before surgeries and more. 
The test measures physiological responses to effort in the cardio-vascular system and in the lungs simultaneously.
The results show maximal oxygen consumption (VO2max), which represents the patient's maximal effort ability.