The 8 Most Common Degenerative Diseases

Degenerative diseases are chronic, they are established little by little and they usually have no cure. Some affect the nervous system and memory, but others have very different symptoms.

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 14 September, 2021

Many of the diseases that humans suffer are acute but then resolve in a matter of days or weeks. In addition, due to the advancement of medicine and scientific knowledge, various pathologies that were previously considered dangerous today are self-limited with the appropriate treatment. Even so, there are still common degenerative diseases that don’t have a cure.

The term degenerative disease is quite generic, since the boundary between “naturally” produced damage and infections is diffuse. Is HIV a degenerative disease because it gets worse over time? Do only conditions that involve the nervous system “degenerate”? Keep reading, as we answer these questions and show you 8 degenerative diseases.

What are the most common degenerative diseases?

According to the National Cancer Institute (NIH), a degenerative disease is any condition in which the function of the organs or tissues involved worsens over time. By definition, a degenerative pathology is chronic (lasting more than 3 months), but not all chronic diseases degenerate in the same way.

Although the terminology may seem complex, we can clarify that no degenerative disease is infectious. A bacterial infection usually worsens over time, but the action is caused by harmful microorganisms, not by an intrinsic mechanism of the patient. In addition, infectious diseases have a general cure, something that isn’t fulfilled in degenerative diseases.

Thus, it is easy to conclude that an infectious disease such as HIV is not degenerative even if it worsens over time without treatment. Neither are injuries or diabetes, since they’re expected to get worse if they aren’t addressed, but they do not cause by themselves in all cases the deterioration of a system or organ in a slow and inexorable way.

However archaic the term may be at a medical level, it is still of relative interest when classifying certain chronic pathologies with a series of characteristic symptoms. Keep reading, because in the following lines we’ll explain the 8 most common degenerative diseases associated with the nervous and muscular systems.

1. Arthritis

Without a doubt, arthritis is one of the most common degenerative diseases in the general population. This term encompasses all those conditions that affect the joints, causing clinical signs such as stiffness, joint pain, swelling, redness, and reduction in the range of motion of the affected limbs.

This set of pathologies is always associated with age. As the CDC indicates, 49.6% of the American population over 65 years of age report a diagnosed arthritis, although the number of actual cases is probably higher. Here are some of the most common arthritic conditions in general society.

1.1 Osteoarthritis (OA)

Osteoarthritis is a type of arthritis characterized by the wear and tear of articular cartilage and friction between bones. Its most common symptoms are joint pain after exercise, swelling of the affected areas, decreased range of motion, weakness, and numbness in the extremities.

In addition to being the most common type of arthritis, OA is the most prevalent joint disorder in high-income regions. According to the NCBI, 10% of American men and 13% of women over the age of 60 develop symptoms of osteoarthritis in the knees. The development of OA may be closely related to the high incidence of obesity in certain countries.

1.2 Rheumatoid arthritis (RA)

Rheumatoid arthritis can be confused with osteoarthritis due to its symptoms, but its origin is different. While OA is associated with mechanical stress and the passage of time, this medical condition has an autoimmune origin. Cells responsible for protecting the body from infection attack healthy joint tissue, resulting in chronic inflammation.

The prevalence of self-diagnosed RA is 1.6% of the adult population. In any case, only 25% of patients who believe they have it actually suffer from it, so its epidemiological burden is estimated at 0.5%. The most common symptoms are the following:

1. Joints tender, swollen, and hot to the touch.
2. Joint stiffness, This clinical sign is differential, as it usually occurs especially when the patient gets up.
3. Tiredness, low-grade fever, and loss of appetite.

Beyond the joints, 40% of RA patients experience symptoms in other areas of the body. For example, scleritis (inflammation of the sclera) may occur in the eyes and a certain proclivity to develop atherosclerosis over time has been recorded. Like all typical degenerative diseases, rheumatoid arthritis has no cure.

1.3 Gout

Gout is a type of inflammatory arthritis characterized by attacks of inflammation in the joints. The pain comes quickly and reaches its peak of onset before 12 hours, accompanied by symptoms such as redness of the area, heat to the touch, and difficulty in moving the affected area. In half of the cases, the condition starts in the joint of the big toe.

Globally, the prevalence of gout ranges from 0.1 to 10%, although the average in high-income countries is 1% of the population. In this case, the underlying cause is clear: the accumulation of urate crystals in the affected joint. For this reason, up to 10% of patients with hyperuricemia will develop gout at some point in their life.

1.4 Ankylosing spondylitis (AS)

In ankylosing spondylitis, there is a chronic inflammation of the joints located in the spine. Although the causes of this clinical condition are unknown, genetics seems to play an essential role: as indicated by the United States National Library of Medicine, most people with AS test positive for the HLA-B27 gene.

The symptoms of this condition are established gradually, with a clear peak of discomfort between 20 and 30 years of age. The most common symptom is constant pain in the lower back or gluteal region combined with a stiff trunk. There is no treatment that can solve ankylosing spondylitis, but it is possible to keep it at bay with medication and surgery.

2. Cancer

With arthritis, we have described four of the most common degenerative diseases in general society. Now it’s time to highlight cancer, the most feared and worrisome group of degenerative pathologies on a medical level.

Cancer is characterized by the uncontrolled growth of a cell line that, unfortunately, has mutated so as not to respond to normal senescence and division processes. Thus, cells proliferate in an exacerbated way and don’t die when touched, promoting the appearance of a tumor that can spread to other parts of the body. This last event is known as metastasis.

Cancer is degenerative by definition, as if it’s not treated, it’ll almost always end up spreading throughout the body. TheWorld Health Organization (WHO) provides us with some interesting data on the epidemiological situation of these malignant neoplasms. We summarize them in the following list:

• Cancer is one of the leading causes of death worldwide. In 2020, this group of diseases was responsible for more than 10 million deaths.
• The most common types are breast cancer (2.26 million cases), lung (2.21 million deaths), colorectal (1.93 million cases), and prostate (1.41 million cases).
• The survival rate is highly variable depending on the type of cancer. 95% of people with testicular cancer recover without problem with treatment, whereas, in all its stages combined, lung cancer has a survival rate of 25% 5 years after diagnosis.

Interestingly, it’s estimated that 80 to 90% of cancers are preventable. Simply not smoking already greatly reduces the chances of developing a neoplasm, since up to half of the people addicted to tobacco die from direct effects derived from its consumption. Leading a proper lifestyle is always the best option.

3. Multiple sclerosis (MS)

Multiple sclerosis is a degenerative, autoimmune disease that affects the brain and central nervous system. In this medical condition, the patient’s own body destroys the myelin sheaths that cover neurons, thus leaving them unprotected. Over time, nerve impulses to different parts of the body slow down or stop.

According to studies, the prevalence of MS is on the rise. It’s much more common in women than in men, with a total of 2.5 million patients worldwide. Symptoms are mostly motor, with a characteristic increase in discomfort in attacks that diminishes slightly in remissions.

4. Parkinson’s disease

Parkinson’s disease is a type of movement disorder. It is a chronic neurodegenerative disorder of the central nervous system that manifests mainly with motor symptoms. The most common are tremors, body stiffness, slower movement of the patient, and clear difficulty walking.

It’s the second most common degenerative nerve disease in the world, second only to Alzheimer’s. It affects about 7 million people worldwide, which is equivalent to 0.3% of the population in high-income regions. It is much more common in elderly people, since the prevalence goes from 1% at 60 years to 4% at 80.

As indicated by the Mayo Clinic, in this pathology some brain neurons decompose and die slowly. Many of the symptoms correspond to the loss of cells that produce dopamine, a neurotransmitter involved in communication between elements of the nervous system. Like the rest of the conditions mentioned (except cancer), it has no cure.

5. Alzheimer’s

Alzheimer’s is one of the most common degenerative diseases, if not the most common in high-income countries. Studies estimate that there are about 47 million people with dementia worldwide and Alzheimer’s is the cause of 60-80% of all cases. Although age is the main predisposing factor for this condition, it isn’t a normal feature of aging.

This condition begins slowly and corresponds to a malfunction of the protein material present in the brain. Due to various imbalances, neural activity cannot take place and neurons lose communication with each other, weaken and die. Its appearance is believed to be triggered by genetic predisposition, environmental conditions, and lifestyle combined.

The symptoms of this neurodegenerative disease are multiple. We group them according to the affected area and the moment of presentation:

• Memory loss: Repeating the same question over again, forgetting events, systematically placing objects in absurd places, getting lost in familiar places, and forgetting the names of relatives.
• Reasoning problems: Difficulty concentrating and thinking, inability to control numerical issues, and worsening performance when multitasking.
• Changes in personality: Depression, social isolation, apathy, irritability, aggressiveness, disorientation, disinhibition, and delusions.

Despite the general difficulty in relating to the environment, patients may have preserved abilities. This means that they often carry out complex tasks even when symptoms get very bad. Since brain involvement is “in parts”, a person with Alzheimer’s may be able to tell stories, speak or sing but lack memory.

Final notes on the most common degenerative diseases

In total, this time we have presented you with 8 common degenerative diseases, with special emphasis on arthritis and its subtypes. It is essential to highlight this pathological group, as it represents that not all conditions of this nature are neurological, as is the case with Alzheimer’s, Parkinson’s, or multiple sclerosis.

Without a doubt, arthritic conditions and cancers represent the most common degenerative pathologies in the world. Malignant neoplasms are the first concern at a social and medical level, since their high prevalence and variable fatality rate make them a pathogenic group of essential priority.