The bronchioles end in tiny air sacs called alveoli, where oxygen is transferred from the inhaled air to the blood. After absorbing oxygen, the blood leaves the lungs and is carried to the heart. The blood then is pumped through your body to provide oxygen to the cells of your tissues and organs.

When you breathe, air travels to your lungs through airways called bronchi. The bronchi divide into smaller airways, called bronchioles, which end in clusters of tiny air sacs, called alveoli.

This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.

Gas exchange between tissues and the blood is an essential function of the circulatory system. In humans, other mammals, and birds, blood absorbs oxygen and releases carbon dioxide in the lungs. Thus the circulatory and respiratory system, whose function is to obtain oxygen and discharge carbon dioxide, work in tandem.

We have here listed 5 important ways for more oxygen:

1. Get fresh air. Open your windows and go outside.
2. Drink water. In order to oxygenate and expel carbon dioxide, our lungs need to be hydrated and drinking enough water, therefore, influences oxygen levels.
3. Eat iron-rich foods.
4. Exercise.
5. Train your breathing.

Lung exercises, such as pursed lip breathing and belly breathing, can help a person improve their lung function. However, it is a good idea to check with a doctor before trying any new exercise, even a breathing exercise. This is especially true for people with underlying health issues, such as COPD.

Over time, the airways become scarred, limiting airflow to and from the lungs. With emphysema, the lung tissue is weakened, and the walls of the air sacs break down. This means less oxygen enters the blood, causing shortness of breath, wheezing and coughing.