There are many people who spend years – decades even – trying to get to the underlying source of their illness. They know they’re sick, they know something is wrong, they know that whatever is plaguing them is making their life unmanageable. They’ve probably been to countless doctors, and each one thinks they’ve found the right diagnosis. Then treatment begins, and nothing changes.
Does this sound like you? If so, read on.
Common Diseases That Are Hard to Diagnose
For one reason or another, many diseases are more difficult to find with conventional diagnostics. This often leads to their remaining undiagnosed or misdiagnosed. Here are some of the most popular ones.
Fibromyalgia

Fibromyalgia is a common illness, yet it still remains very mysterious to modern medicine. Symptoms include:
- Muscle soreness and tenderness
- Pain points – pain regions
- Fatigue
- Inability to get restful sleep
- Brain fog – “fibro fog”
- Stiffness
- Depression
We aren’t sure what causes fibromyalgia, but there are factors that correlate with it.
- Stressful events, either physical, emotional, or both
- Repetitive injuries
- Autoimmune diseases such as lupus or rheumatoid arthritis
Fibromyalgia is often diagnosed via process of elimination. That is to say, if other conditions that could be causing your symptoms are ruled out, then fibromyalgia is the common diagnosis.
Brain Inflammation

The brain itself doesn’t feel any pain, so when brain inflammation occurs, it’s noticed as a series of symptoms that seem unrelated to the brain itself.
- Brain fog – fuzzy thinking, memory loss, inability to concentrate
- Depression and anxiety
- Anger
- Irritability
- Fatigue
Brain injuries are commonly attributed to brain inflammation, as well as chronic body inflammation, leaky gut, high blood sugar, hormone imbalances, food intolerances, and chronic stress.
Autoimmune Diseases

An autoimmune diseases occur when the body mistakes its own tissue and chemistry as foreign to the body and thus unleashed an attack on itself. This occurs through the release of autoantibodies, which are usually meant to fight bacteria and viruses.
There are many different kinds of autoimmune diseases that cause a number of different symptoms, but there are some common symptoms that most people experience with any kind of autoimmune disease:
- Chronic pain
- Fatigue
- Digestive problems – diarrhea or constipation
- Memory loss – “brain fog”
- Anxiety and depression
- Insomnia
- Weight loss or weight gain
Below are some common autoimmune diseases.
Inflammatory Bowel Disease
IBD involves the inflammation of the intestinal wall. There are different kinds of IBD. For instance, Crohn’s disease is an inflammation of the GI tract, while ulcerative colitis is an inflammation of the large intestine and rectum.
Grave’s Disease
A problem of the thyroid gland in which it produces an excess amount of hormones (these hormones control metabolism).
This causes the body to “redline”, so to speak. Symptoms include anxiety, racing heart, heat intolerance, and difficulty maintaining weight.
Hashimoto’s Thyroiditis
Otherwise known simply as Hashimoto’s disease, this involves a failure of the thyroid to produce enough hormones, causing a swelling of the thyroid, sensitivity to cold, weight gain, chronic fatigue, and hair loss.