Aspiration Pneumonia – Causes, Risk Factors, Symptoms, Signs & Tests, Treatment, Complications

Breathing in foreign material (Infectious agents) from the immediate surroundings is a common way of getting infection. The infectious agents eventually enter the lungs and its airways through the respiratory tract.

The inflammation of the lungs caused by infectious agents inhaled during breathing is called as Aspiration pneumonia. The source of infectious agents may include food items, liquids, fluids present in the mouth or even vomit.

A chemical pneumonitis is developed due to the acidity of oral or gastric aspirate. The inflammation is further enhanced by activities of bacterial pathogens.

Once the infectious agent reaches the lungs, it may lead to following conditions.

• Lung Abscess (Collection of pus in the lungs)

• Swelling

• Inflammation in the lung

• (Pneumonia) Infection in the lung

Causes of Aspiration Pneumonia

The causes of Aspiration Pneumonia comprises of various methods that facilitates the entry of infectious agents into the lungs.

• Medicines or due to other illness

• Incompetent swallowing mechanism

• Coma

• Neurological disease like strokes

• Disorders of the oesophagus

• Consuming large quantity of alcohol

• Application of General anaesthesia

The causative agent may be anaerobic bacteria or aerobic bacteria.

Anaerobic oral flora including Bacteroides, Prevotella, Fusobacterium and Peptostreptococcus

Aerobic Bacteria including Streptococcus pneumonia, Staphylococcus aureus, Haemophilus influenza and Pseudomonas aeruginosa.

Risk Factors

• Old age patients

• Individuals with poor gag reflex

• Unconscious or semi-conscious patients after a stroke or brain injury

• Individuals with problems in swallowing


The symptoms of aspiration pneumonia are similar to other types of Pneumonia.

• Cough with sputum

• Sputum with pus or bloody sputum or greenish sputum

• Bluish skin/skin discoloration due to lack of oxygen

• Fever

• Shortness of breath

• Chest pain

• Fatigue

The other associated symptoms of aspiration pneumonia comprises of difficulty in swallowing,

breathe odour and excessive sweating.

Signs and tests

The diagnosis of Aspiration pneumonia is done by taking into consideration the following results.

• Clinical circumstances

• Radiologic findings

• Microbiologic cultures

· Doctors may recommend various tests for diagnosing the presence of aspiration pneumonia.

• Physical examination

• Chest x-ray

• Complete blood count (CBC)

• Sputum culture

• CT scan of the chest

• Bronchoscopy

• Arterial blood gas

• Blood culture

• Swallowing studies


The treatment of Aspiration Pneumonia varies depending on the severity of the pneumonia. The antibiotics are prescribed for treating bacteria that had caused the infection.

Patients with complications may need to get hospitalized; otherwise treatment can be done at home. Doctors may prescribe special antibiotics for treating bacteria that resides in the mouth.

Doctors determine the type of pneumonia causing bacteria on the basis of various factors such as

Health of patient, place of patient residence, medical history of patient, recent medications including antibiotics, etc.


The complications of the aspiration pneumonia comprise of serious health conditions.

• Acute respiratory distress syndrome (ARDS)

• Pneumonia

• Lung abscess

• Bacteraemia

• Septicaemia

• Low blood pressure