Alveolitis can refer to two inflammatory

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 conditions. It can refer to inflammation of the alveoli

Pulmonary alveolus

An alveolus is an anatomical structure that has the form of a hollow cavity. Found in the lung parenchyma, the pulmonary alveoli are the dead ends of the respiratory tree, which outcrop from either alveolar sacs or alveolar ducts, which are both sites of gas exchange with the blood as well...

 in the lung

Lung

The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...

s, or the dental alveolus

Dental alveolus

Dental alveolus are sockets in the jaws in which the roots of teeth are held in the alveolar process of maxilla with the periodontal ligament. The lay term for dental alveoli is tooth sockets...

 in the jaw.

Alveolus in the jaw is also known as dry socket. This type of inflamed tooth socket is usually seen after tooth extractions in smokers or people with diabetes.

Alveolitis is the accumulation of inflammatory and immune effector cells within the alveolar walls and spaces.

Extrinsic allergic alveolitis is a lung disorder resulting from repeated inhalation of organic dust, usually in a specific occupational setting. In the acute form, respiratory symptoms and fever begin eighteen hours after exposure to the dust. The chronic form is characterized by gradual changes in the lung tissue associated with four years of exposure to the irritant. This may eventually lead to Interstitial lung disease.