DISEASES OF THE
LUNG
Dr. zameer pasha
Anatomy
Types of lung diseases:
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Airway diseases -- These diseases affect the tubes (airways)
that carry oxygen and other gases into and out of the lungs.
These diseases cause a narrowing or blockage of the airways.
They include asthma, emphysema, and chronic bronchitis.
People with airway diseases sometimes describe the feeling as
"trying to breathe out through a straw."
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Lung tissue diseases -- These diseases affect the structure
of the lung tissue. Scarring or inflammation of the tissue
makes the lungs unable to expand fully ("restrictive lung
disease"). It also makes the lungs less capable of taking up
oxygen (oxygenation) and releasing carbon dioxide. Pulmonary
fibrosis and sarcoidosis are examples of lung tissue diseases.
People sometimes describe the feeling as "wearing a too-tight
sweater or vest" that won't allow them to take a deep breath.
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Pulmonary circulation diseases -- These diseases affect the
blood vessels in the lungs. They are caused by clotting,
scarring, or inflammation of the blood vessels. They affect the
ability of the lungs to take up oxygen and to release carbon
dioxide. These diseases may also affect heart function.
Common lung diseases –
Asthma
 Chronic bronchitis
 COPD (chronic obstructive pulmonary disease)
 Emphysema
 Pneumonia
 Tuberculosis
 Lung cancer
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Asthma
◦ Asthma is an inflammatory disorder of the airways,
which causes attacks of wheezing, shortness of breath,
chest tightness and coughing.
Common triggers of asthma –
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Animals (pet hair)
Dust
Changes in weather (most often cold weather)
Chemicals in the air or in food
Exercise
Pollen
Respiratory infections, such as the common cold
Strong emotions (stress)
Tobacco smoke
Emergency symptoms:
 Bluish color to the lips and face
 Decreased level of alertness such as severe drowsiness or
confusion, during an asthma attack
 Extreme difficulty breathing
 Rapid pulse
 Severe anxiety due to shortness of breath
 Sweating
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Atelectasis (collapse)
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Incomplete expansion of the lungs or collapse of previously inflated
lung substance.
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Types of atelectasis
1.
Resorption atelectasis.
2.
Compression atelectasis.
3.
Contraction atelectasis.
Resorption atelectasis
Result from complete obstruction of an airway and absorption of
entrapped air.
Compression atelectasis
Results whenever the pleural cavity is partially or completely filled by
fluid, blood, tumor or air.
Contraction atelectasis.
Local or generalized fibrotic changes in pleura
or lung preventing full expansion of the lung.
Atelectatic lung is prone to develop superimposed
infection.
It should be treated promptly to prevent hypoxemia.
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Chronic Obstructive Pulmonary Disease (COPD)
A group of conditions characterized by limitation of airflow
it is one of the most common lung diseases
There are two main forms of COPD:
◦ Chronic bronchitis: which involves a long-term cough
with mucus
◦ Emphysema: which involves destruction of the lungs
over time
Most people with COPD have a combination of both
conditions.
Chronic bronchitis: clinically it is defined as a cough
with sputum production on most days for 3 months of a
year, for 2 consecutive years.
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Emphysema: Emphysema is an enlargement of the air
spaces distal to the terminal bronchioles, with destruction
of their walls.
Types –
◦ Centriacinar: Centrilobular emphysema
◦ Panacinar: Panlobular emphysema
◦ Paraseptal: Paraseptal emphysema
◦ Irregular
Causes◦ Smoking; Occupational exposures; Air pollution;
Genetics ; Autoimmune disease
One of the most common symptoms of COPD is shortness
of breath (dyspnea).
a persistent cough, sputum or mucus
production, wheezing, chest tightness, and tiredness.
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Bronchiectasis
Chronic necrotizing infection of the bronchi and bronchioles
leading to abnormal dilatation of these airways.
Clinical course:
◦ Sever persistent cough with sputum (mucopurulent, fetid
sputum) sometimes with blood.
◦ Clubbing of fingers.
◦ Rare complications: metastatic brain abscess and
amyloidosis.
Pneumonia: is defined as acute inflammation of the lung
distal to the terminal bronchioles. (respiratory bronchiloes,
alveolar ducts, alveolar sacs & alveoli).
 Types –
 Based on etiology
◦ Bacterial
◦ Viral
◦ Others – aspiration, hypostatic, lipid.
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Based on area affected
◦ Lobar pneumonia – part of lobe, entire lobe, or two lobes
◦ Lobular pneumonia – only terminal bronchiloes and alveoli.
◦ Interstitial pneumonia – inflammation confined to interstitial
tissues of the lung without any alveolar exudate.
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Pathologic changes –
Lobar ,Lobular pneumonia shows patchy areas of red and
grey hepatisation, acute bronchiolitis
◦ Clinical features: chills, fever, malaise, chest pain,
dyspnoea and cough with expectoration.
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Lung cancer – most common primary cancer of the lung is
bronchogenic carcinoma (95%). Lung is also the
commonest site for metastasis from carcinomas and
sarcomas.
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Bronchogenic carcinoma – most common tumor in men.
Etiology
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Smoking – quantity, type
Atmospheric pollution
Occupational cases
Dietary factors – contributing factor
Genetic
Clinical features:
 Cough
 Chest pain
 Dyspnoea
 Haemoptysis
 Symptoms due to metastasis.
Histologic types:
squamous cell carcinoma
small cell carcinoma
adenocarcinoma
large cell carcinoma
adenosquamous carcinoma
Lung carcinomas spread both by lymphatic and
hematogenous pathways.
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References:
◦ Robbins basic pathology – Kumar et al
◦ Essential pathology for dental students – Harsh Mohan
Thank you