Cavity? Or just a disproportionate chest? Hard to answer without knowing your age. Some parts of the the body grow at different rates, and from around 12 to 18 or so, your body can look very strange if you lokk too closely. It is possible you have a problem with growth hormone or some other developmental problem. If it worries you, take the question to your doctor. Some people have an extra pair of ribs at the bottom of the chest, and this can cause what some call a "sunken chest" look. It's not that unusual and it will not hurt you.
Hemothorax is a medical term meaning blood in the chest cavity.
Chest cavity
The heart is within the chest cavity. It is located medially in the chest cavity.
Disproportionate
The function of the chest cavity is to support some internal organs. The lungs and the heart are located in the chest cavity which protects and supports them.
chest cavity (Laryngeal cavity)
The chest cavity increases in size during inhalation
The space in your chest cavity increases.
Increases .
The movement of the diaphragm affects the size of the chest cavity by when you inhale the chest cavity enlarges, but when you exhale the chest cavity becomes smaller.
The pericardial cavity. Try the chest, or thoracic cavity.
The cavity that you are referring to is know as the thoracic cavity.The ventral body cavity contains the organs in the chest and abdomen.Thoracic cavity