Superficial to the gland is the sternum. Lying deep to the thymus are the great vessels and the cranial part of the pericardium. The two lobes of the gland differ in size, and in many individuals the right lobe overlaps the left lobe. The thymus is about 5 cm long, 4 cm wide, and 6 mm thick.
Signs and Symptoms of Emphysema Symptoms of emphysema vary from mild to severe and include shortness of breath (dyspnea), cough, and difficulty breathing upon exertion (e.g., exercise). Emphysema is a chronic (long lasting), progressive condition, which means the symptoms usually worsen over time.
Emphysema destroys alveoli, which are air sacs in the lungs. The air sacs weaken and eventually break, which reduces the surface area of the lungs and the amount of oxygen that can reach the bloodstream. This makes it harder to breathe, especially when exercising. Emphysema also causes lungs to lose their elasticity. Emphysema is one of the two most common conditions that fall under the umbrella term chronic obstructive pulmonary disease (COPD). The other major COPD condition is chronic bronchitis. Emphysema is an irreversible condition, so treatment aims to slow its progression and minimize symptoms.