Constantly feeling sick can come from poor sleep, stress, infections, anemia, or other conditions. See a doctor if it persists.
Common causes
- Poor sleep.
- Stress and anxiety.
- Anemia.
- Dehydration.
- Viral infections.
- Thyroid problems.
- Diabetes.
- Depression.
- Medicine side effects.
What to do
Track symptoms, sleep well and eat balanced meals.
See a doctor
If you feel sick for weeks, have weight loss, fever or fatigue.
Frequent causes by category
Constant nausea or a general sick feeling has many causes. Common ones include poor sleep, anemia, thyroid disease, depression and anxiety, infections, pregnancy, medication side effects and chronic conditions such as diabetes or celiac disease. Persistent fatigue lasting more than six months with unrefreshing sleep may meet criteria for myalgic encephalomyelitis (chronic fatigue syndrome).
- A basic workup usually includes a complete blood count, thyroid hormone (TSH), glucose or HbA1c, kidney and liver panels, and vitamin D and B12.
- About 1 in 5 adults in the US has an anxiety disorder in a given year, according to NIMH, and physical symptoms like nausea are common.
- Acid reflux and gastritis often cause morning nausea.
- Dehydration and skipped meals can produce a sick feeling within hours.
Tracking symptoms
A two-week symptom diary of food, sleep, stress, medications and timing helps a doctor spot patterns. Warning signs such as unexplained weight loss, blood in stool or vomit, fever, night sweats, jaundice or severe abdominal pain call for prompt care. If feelings of hopelessness accompany the symptoms, a mental health professional should be included in the care plan.
Common categories
Feeling sick often can be due to poor sleep, stress, anemia, thyroid disease, diabetes, depression, infections, food intolerance or medications. A common cause is iron deficiency, which affects about 10 percent of women of childbearing age in the US.
What to do
Track symptoms, sleep, diet and stress for two weeks. A doctor can order tests such as complete blood count, thyroid function, glucose and vitamin levels. See a doctor if there is weight loss, fever, persistent vomiting, or symptoms lasting weeks.
Symptoms worth investigating
Constant sickness feelings can come from persistent fatigue, nausea, dizziness, chronic infection, anemia (hemoglobin below 12 g/dL for women and 13.5 g/dL for men), diabetes, autoimmune disease, sleep apnea, depression and anxiety. Long COVID symptoms include fatigue, brain fog and breathlessness for months. About 1 in 5 adults who had COVID reported long COVID symptoms in some surveys.
Preparing for a doctor’s visit
Write down when symptoms started, triggers, medications and supplements, alcohol and caffeine use. A routine workup may include a blood count, metabolic panel, thyroid hormone (TSH), vitamin D and B12, and inflammation markers. Call urgently for chest pain, severe breathlessness, fainting, confusion or unexplained weight loss.
Based on data from the Mayo Clinic and the CDC
