What is the most common cause of shortness of breath?
Allergic reaction or anaphylaxis, sudden blood loss, anemia, Anxiety, Foreign body or choking, lung infections like pneumonis, Fluid in lung, Collapse lung, Blood clot in lung vasculature like Pulmonary embolism, Asthma, COPD, Pregnancy, Heart attack or failure, Heart rhythm irregularity.
There is no scientific proof to methods available online to detox your lungs. Fortunately, Lungs are good at cleaning and repairing themselves unless there was any chronic damage done. You may follow some steps to keep the lungs healthy such as Quit smoking, avoid second-hand smoke, steer clear of pollution indoors & outside (Wear mask, use air purifiers), prevent lung infections (Hand washing, maintain distance from sick people, get flu/pneumonia vaccines), include anti oxidants in diet and do breathing exercises or any physical activity on regular basis.
From limited research done, coffee consumption was associated with some positive effects on the respiratory system. Few small studies have shown coffee was associated with reduction of asthma and coffee with natural honey was effective for persistent post-infectious cough. There was however limited available evidence to establish its effects.
At home, you may check your lungs functioning with an instrument named "Peak Flow meter". It is a small hand held device, when you blow air into it, it calculates the lung capacity and expansion. Spirometer is another instrument which helps in similar way in lung assessment and additionally it also has therapeutic usage. You may check oxygenation level by "Pulse Oximeter" which gives indirect clue on lung damage but keep in mind there are other medical conditions which may affect pulse oximeter readings.
Fat accumulation around waist needs lifestyle modifications in the form of diet and exercise. Do portion control of meals and include low carbohydrate, low fat and high protein foods in diet. Moderate to high intensity exercises such as jogging, running, lifting weights and crunches are to be done for at least 5 days in a week and each session must be at least 45 minutes.