Pneumonia and respiratory failure are not comorbidities. Those would be the actual cause of death with COVID given the credit for bring them on.

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Common comorbidities associated with COVID-19 deaths have been well-documented across various studies and data sources, primarily reflecting conditions that increase vulnerability to severe outcomes. Based on extensive data, especially from the U.S. and other heavily impacted regions, the most frequent comorbidities include:

- *Hypertension (High Blood Pressure):* This tops the list in many analyses. In the U.S., CDC data from March to October 2020 showed 56% of adults hospitalized with COVID-19 had hypertension [1], and it’s consistently cited in mortality stats. A New York City study of 5,700 hospitalized patients in early 2020 reported it in 56.6% of cases [2], while globally, a meta-analysis pegged its prevalence at 32% among all COVID-19 patients and 35% in fatal cases [3].

- *Diabetes:* Another major player, often linked to worse outcomes due to impaired immune response and blood sugar control issues. The same NYC study found it in 33.8% of patients [2], and CDC data noted 41% of hospitalized adults had metabolic diseases, including diabetes [4]. Globally, it ranged from 8.2% in China (early 2020 data) to 17.4% across broader reviews, with higher rates (up to 33%) in severe or fatal cases [5].

- *Cardiovascular Disease:* This includes conditions like coronary heart disease and heart failure. It appeared in 11.7% of cases in a 2020 meta-analysis [3] and was notably prevalent in fatal outcomes—26% of 814 COVID-19 deaths in Romania, for instance [6]. In the U.S., myocardial infarction and congestive heart failure were tied to higher mortality odds in a 2020 study of 31,461 patients [7].

- *Obesity:* A significant risk factor, especially in Western populations. The NYC cohort reported it in 41.7% of patients [2], and a 2021 CDC report flagged it as one of the strongest chronic risk factors for COVID-19 death among hospitalized adults, alongside diabetes with complications [8].

- *Chronic Pulmonary Disease:* Conditions like COPD or asthma showed up in 17.5% of U.S. patients in the 2020 Charlson comorbidity study [7] and were linked to higher mortality risk (e.g., HR 2.68 in China’s early data) [9]. Respiratory failure, often a direct result of COVID-19, complicates this category but underscores lung vulnerability.

- *Renal Disease:* Chronic kidney disease was a standout in multiple reviews, with a hazard ratio of 3.48 for death in a UK study [10]. It’s less prevalent overall (0.8% in some global data) but deadly when present, especially in older patients [3].

- *Cancer:* Malignancies, particularly metastatic ones, increased mortality odds (HR 3.50 in China, 2020) [9]. Prevalence was lower (1.5% globally), but the impact was outsized in fatal cases [11].

Other notable mentions include dementia, liver disease (mild to severe), and immunosuppression, though these were less common. Age amplifies these risks—over 65s with comorbidities faced death rates 4 to 10 times higher than those under 40, per UK data from 2021 [12]. Multimorbidity (multiple conditions) was also a game-changer; over half of fatal cases in some studies had two or more comorbidities, with one U.S. analysis noting an average of 2.6 to 4 additional conditions per death [13].

These patterns held steady from 2020 through 2023, with the CDC reporting that 94-95% of U.S. COVID-19 deaths involved comorbidities [14]. The virus didn’t just exploit these conditions—it often triggered acute complications (e.g., pneumonia, ARDS) that were listed alongside chronic issues, muddying the “cause of death” debate. Still, the data’s clear: these comorbidities didn’t just coexist; they stacked the deck against survival.

### References
[1] https://www.cdc.gov/mmwr/volumes/69/wr/mm6943e3.htm
[2] https://jamanetwork.com/journals/jama/fullarticle/2765184
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7365650/
[4] https://www.cdc.gov/mmwr/volumes/70/wr/mm7010e4.htm
[5] https://www.thelancet.com/journals/landia/article/PIIS2213-8...
[6] https://www.nature.com/articles/s41598-021-84705-8
[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7439986/
[8] https://www.cdc.gov/pcd/issues/2021/21_0123.htm
[9] https://erj.ersjournals.com/content/55/5/2000547
[10] https://www.bmj.com/content/374/bmj.n1648
[11] https://www.thelancet.com/journals/lanonc/article/PIIS1470-2...
[12] https://www.ons.gov.uk/peoplepopulationandcommunity/healthan...
[13] https://www.cdc.gov/nchs/nvss/vsrr/covid19/health_disparitie...
[14] https://www.cdc.gov/nchs/nvss/vsrr/covid_weekly/index.htm