Lower respiratory infections

Lower respiratory tract infections affect the lungs and trachea. Infections such as bronchitis and pneumonia accounted for 5.6% of all deaths in 2015, down from 6.5% in 2000.

As usual, the improvement differs based on country. In Ireland, the chance of a 30-49 year old adult dying of a lower respiratory tract infection reduced from 0.32% to 0.09% in that time. Note that Ireland banned smoking in workplaces from 2004, which i believe made a huge difference, as you can see in the chart:

While there are other kinds of infection such as adenovirus and influenza, these days the most serious are bronchitis and pneumonia.

Bronchitis is an inflammation of the walls of the large airways in the lungs that makes it more difficult for your body to breath in enough air. This results in coughs and wheezes as the body tries to clear out what it things is an obstruction.

There are two categories of bronchitis – acute and chronic.

Acute bronchitis is usually quite short, lasting about three to six weeks, and is mostly (90%) caused by viral infection due to close contact with people. Environments that are smoky, dusty or otherwise polluted exacerbate the infection. If you visit somewhere that’s densely populated and dirty (such as a city) and come back with a cough, this is probably bronchitis. About 5% of all adults are affected by acute bronchitis, but it’s usually not serious.

To avoid bronchitis, don’t smoke, and keep your hands clean.

Chronic bronchitis is more serious, as it means your body is not overcoming the issue. If your bronchitis lasts more than three months, and comes back the next year for another three months, your doctor will treat this as chronic bronchitis. About 60% of all lower respiratory infection deaths are caused by chronic bronchitis. It has its own section in this book (chronic obstructive pulmonary diseases)

Pneumonia is an inflammation of the alveoli in the lungs. These are the tiny sacs that extract oxygen from the air. It is usually caused by infection from virus or bacteria. If you have a generally bad health, you are more likely to contract this.

About 7% of all people are affected by pneumonia, with 1% of those affected dying (that’s 4% of all deaths in the world). Pneumonia is mainly a danger in very old, very young, or chronically ill people.

Pneumonia mostly stabilises within 3-6 days, with the symptoms resolving over the next few weeks.

Because pneumonia is more likely to appear once you already have a compromised health, it has been known as the “old man’s friend” by some, because it is seen as an end to the underlying disease.

For the same reason (compromised health letting it gain a foothold), pneumonia is the most common hospital-acquired disease.

18% of all deaths of children under 5 are caused by pneumonia. Mostly (95%) in developing countries.

To avoid dying of pneumonia, keep your hands clean, don’t smoke, and make sure you and your children are vaccinated against haemophilus influenzae and streptococcus pneumoniae.

Vaccinating against other diseases such as pertussis, varicella and measles also helps, as if you contract those diseases, your immune system can be overworked, allowing pneumonia to take hold.

In general, just vaccinate yourself.