The Roaring 20s: Common Illnesses in Young Adulthood

This post was first published on September 26, 2014. It has been updated on August 25, 2017

Most think of their 20s and early 30s as an extended adolescence: all the health that teens enjoy, plus the independence that has been craved. But for many 20-somethings, the “health” part isn’t necessarily a given. Here are some illnesses that refuse to steer clear of young adulthood.

health risks for college students The Roaring 20s: Common Illnesses in Young Adulthood Photo

Common Illnesses

Bipolar Disorder

Bipolar disorder (BPD) begins before age 20 in 1 of every 5 sufferers, but the estimated average age of onset is the early 20s. BPD is characterized by violent mood swings: “high” periods of energy, confidence, and manic activity, and “low” periods of depression and inactivity. These mood swings can make life unpredictable and unmanageable for those who suffer from them and those who care for them. Many different mental health professionals can treat BPD, but treatment should come from practitioners who specialize in mental health.

Initial diagnoses should be given by a psychologist or psychiatrist, and medications can be prescribed only by the latter. Symptoms that are dangerous to anyone, including the patient, should be brought to immediate medical attention; the emergency room is equipped to handle both suicidal and manic behavior, and so are inpatient psychiatric hospitals.

To learn more about bipolar disorder, read our patient guide.

Multiple Sclerosis

Multiple Sclerosis (MS), a neuroinflammatory disease which sometimes causes severe disability, is the most common disabling neurological disease of young and middle-aged adults. Its root causes are largely mysterious. Symptoms and disease course vary widely, with some sufferers experiencing a steady decline in sensory and motor function, and others an long-term decline with periods of remission. Symptoms include fatigue, dizziness, tingling or zapping sensations, localized numbness, incontinence, tremors and unsteady walking. Treatments are available, however, to control the symptoms, and they are usually provided by neurologists.

To learn more about multiple sclerosis, read our patient guide.


Schizophrenia impacts no less than 1% of the population, and it is usually diagnosed between ages 16 and 30. It is considered much harder to diagnose in teens, so definitive diagnoses are usually given for those in their 20s. Symptoms of schizophrenia include “positive” symptoms (which are anything but; they refer to behaviors that healthy people do not display), “negative” symptoms (which refer to the absence of normal behaviors), and cognitive symptoms. Positive symptoms are the ones most strongly associated with schizophrenia, and include delusions, hallucinations, movement disorders and thought disorders. Negative symptoms include flat affect and an inability to enjoy regular life activities. Cognitive symptoms include poor “executive functioning” or decision-making skills. Only physicians with mental health expertise should treat schizophrenia.

To learn more about schizophrenia, read our patient guide.


Allergy symptoms include congestion and sneezing, itchy, watery eyes, itchy skin, wheezing, and rash. Seasonal allergies can arise from plants, pollen, or molds. Allergies to animal dander and foods are also common in young people. All are thought to have a hereditary component, and affect as many as one in four people annually in industrialized countries. Your general practitioner will probably refer you to an allergist, if your symptoms make an allergic reaction likely.

To learn more about allergies, read our patient guides:


Lupus is an autoimmune disease that flares up and goes into remission. Lupus causes your body’s autoimmune system to attack its own healthy tissues; this results in pain, swelling, fatigue, and weakness. It is most likely to strike between ages 15 and 44 and is most commonly diagnosed in women in their 20s and 30s. The usual specialist to see for lupus treatment is a rheumatologist.

To learn more about lupus, read our patient guide.

Vitamin Deficiency

Lifestyle changes, such as moving to a new area, are a common reason for vitamin and mineral deficiencies, typically signaled by eye, hair, nail, mouth and skin symptoms. Vitamin D deficiency is the most common deficiency in the U.S. and impacts young adults frequently. Symptoms can be weak and variable, though they often include persistent aches and muscle weakness. Vitamin D deficiency is more commonly identified through blood tests. In the long term, it can pose serious health risks, but it is easy to treat with improved diet, supplements and moderate exposure to sunlight; your general practitioner can also help you decide on the best treatment.

Less Common Illnesses

Those are some fairly common illnesses that strike in the 20s and 30s, but there are others to be aware of. Here are three of the less common illnesses that typically develop during these years, along with their treatments and the type of doctors who diagnose and treat them.


Narcolepsy, a chronic brain disorder, is believed to affect 1 in 3,000 Americans. It is most likely to be diagnosed in men in their 20s. Symptoms include excessive daytime sleepiness (EDS), a sudden loss of muscle tone (aka. cataplexy), hallucinations, disruption of normal nighttime sleep and even temporary paralysis while falling asleep or waking up. The best treatment for narcolepsy is often achieved by seeing a specialist; these are usually neurologists who specialize in diagnosing and treating sleep disorders.

Cluster Headaches

Although they are the least common kind of a headache, cluster headaches can also be the most severe variety. Thought to follow circadian rhythms, cluster headaches appear in episodes one to three times daily during each “cluster period,” which can last from two weeks to three months. They usually come at the same time each year, and their triggers are often similar to those for migraines. Neurologists should be consulted for the diagnosis and treatment of cluster headaches.

Lyme Disease

Lyme disease is caused by bacteria carried by ticks, so people who spend lots of time outdoors are more likely to get it. Symptoms include fever, headache, fatigue, and a rash. If left untreated, more serious problems with the heart, joints, and nervous system can develop. Lyme disease is treated with antibiotics and can be treated by any physician. To learn more about lyme disease, read our patient guide.

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