Pneumonia uniquely targets the alveoli, small sacs crucial for oxygen and carbon dioxide exchange in the lungs. The lungs, divided into right and left lobes, facilitate air movement through branching airways, culminating in these grape-like structures. Pneumonia induces inflammation and fills the alveoli with infected fluid, disrupting the essential gas exchange process. Consequently, this interference results in breathing difficulties and chest pain, highlighting the significant impact of pneumonia on respiratory function.

Infections typically lead to fever, which can range from low-grade to high-grade, depending on the severity of the infection.

dyspnea (shortness of breath), chest pain, and coughing, which helps clear the fluid from the air sacs.

The most common causes of pneumonia are bacteria and viruses, with Streptococcus pneumoniae and the flu virus being significant culprits.

Community-acquired pneumonia refers to infections picked up in everyday environments from other people.

Ventilator-acquired pneumonia is associated with patients on ventilators, where organisms can enter the airway directly through the tube.

Aspiration pneumonia occurs when foreign substances, such as vomit or food, are accidentally inhaled into the lungs due to the epiglottis failing to close off the airway.

• The flu vaccine protects against the influenza virus, which can cause severe illness.

• There are trivalent (protecting against three strains) and quadrivalent (protecting against four strains) versions of the flu vaccine.

• The flu virus changes every year, and vaccines are updated to protect against the most likely strains.

• Inactivated vaccines use a killed virus to stimulate the immune system's response.

• Pneumococcal vaccines protect against diseases caused by pneumococci bacteria, including pneumonia, ear infections, and meningitis.
• Multiple versions of the pneumococcal vaccine exist, offering protection against a range of bacterial strains.
  

Emphysema, a form of COPD, involves the destruction of elastin, a protein providing elasticity to airway walls. This loss results in the collapse of airways and the formation of floppy, bag-like alveoli. The typical spring-like recoil action of the lungs, facilitating air expulsion, is compromised in emphysema due to the structural changes, leading to impaired respiratory function.

In emphysema, destruction of elastin leads to a loss of airway wall structure.

Airway walls no longer provide proper recoil, and as a result, the air gets trapped within the lungs.

Airway walls in the stem of the airway can collapse, causing a physical obstruction.

People with emphysema may exhibit a "barrel chest" appearance due to their altered lung shape.

They can appear pink instead of blue due to an adequate oxygen supply.

"Pink puffers" is a nickname for emphysema patients, emphasizing their relatively normal oxygen levels.

They often use pursed-lip breathing to help maintain airflow in obstructed airways.

Pursed lips and slower breathing aim to keep airways open longer, compensating for reduced expiratory airflow.

When assessing a person with shortness of breath and suspecting emphysema, several diagnostic tests can help confirm the condition.

The first test that may be performed is a chest x-ray, which can reveal characteristic signs of emphysema.

A normal chest x-ray shows well-defined lung shapes and a diaphragm that aids in breathing.

In contrast, an individual with emphysema will have hyper-inflated lungs, resembling puffed-out bags, with collapsed airways leading to this appearance.

The pressure from the hyper-inflated lungs can flatten the diaphragm, making it harder for the person to breathe. Extra neck and abdominal muscle use can also be observed.

Lung cancer originates when a cell becomes damaged or mutated, leading to uncontrolled growth.

Cancer cells obstruct airways, resulting in wheezing, decreased lung function, and airflow restriction.

Lung cancer increases susceptibility to lung infections due to the inability to clear bacteria past cancerous cell masses.

Lung cancer prompts immune response, causing fever due to immune cell activity.

White blood cells migrate to lung infections to combat bacteria, leading to swelling and worsening symptoms.

Lung cancer patients experience significant energy demands, contributing to unintentional weight loss.

Cancer cells secrete an enzyme that breaks down lung tissue, allowing invasion of nearby structures.

Lung cancer cells may migrate into blood vessels, leading to metastasis to other organs.

They can also penetrate the lung lining, causing further swelling and breathing difficulties.

Medical imaging involving radiation, like x-rays and CT scans, can contribute to cell mutations.

Radon, a naturally occurring gas, can accumulate in homes and raise lung cancer risk.

Main causes include smoking, with a measure called "pack years" indicating risk.

It occurs in heavy smokers, mainly females with a long smoking history.

SCLC is highly aggressive, dividing and spreading rapidly throughout the body.

NSCLC constitutes 85% of lung cancer diagnoses.
This category has subtypes based on different mature cell types in the respiratory tract.

The choice of lung cancer treatment depends on the cancer's stage and type.

Surgical resection, radiotherapy, and chemotherapy are the primary treatment options, each with its unique considerations and potential side effects.

Effective cancer care involves close collaboration with healthcare professionals and regular follow-up appointments to ensure patient well-being and monitor long-term outcomes.