Even after 12 hours of sleep, I'm so exhausted it's hard to get out of bed. Some days, I get going by mid-morning; other days, it's noon or later. Fatigue and aching joints go with me everywhere.

Chills, fever and headaches last for months. The calves of my legs swell. If it isn't that, it's chest pain, nausea or dizziness, perhaps facial numbness, pallor or a fast heartbeat. These things come and go. So does my ability to concentrate and remember.

I'm sick with an incurable disease called chronic Epstein-Barr virus infection, and it may affect someone you know. Hundreds of us -- twice as many women as men -- are documented victims, and countless others are afflicted but don't know the reason for their misery.

I used to teach in elementary school, but I no longer have the stamina. Like most people with this disease, I'm not an invalid -- but I am limited. I have to lie down every few hours, even if I've only been reading. My life has become streamlined.

Before I fell ill, I used to ride horseback after school, fix dinner, then grade papers until bedtime. Today, I will complete little in the eight or so hours I will be awake. By the time I finally get going and finish the dishes or write for an hour, my productivity for the day has ended. I wrote this article over a period of months, a few paragraphs at a time.

The victims of this disease are unable to completely suppress the Epstein-Barr virus (EBV), one of the herpes viruses and possibly the most common of all viruses infecting human beings.

Like its relatives -- the herpes viruses that cause chicken pox, shingles, cold sores and genital herpes -- the Epstein-Barr virus is found everywhere there are people. It is spread primarily by direct contact, such as from a shared drinking glass or by tiny saliva particles expelled in a cough or sneeze.

Discovered in 1964, EBV was first associated with Burkitt's lymphoma, a cancer found in children in Africa. Later, the virus was linked with nose and throat cancers in Asia, with B-cell lymphoma -- a lymph system cancer -- and with nonmalignant illnesses such as encephalitis, hepatitis and chronic EBV infection.

In developed countries, EBV commonly shows up as infectious mononucleosis, or mono. Characterized by excessive fatigue and sore throat, mono seldom is serious; recovery comes within a month or so.

Although many people are exposed to EBV, few become ill. Most people's defense system kills EBV just as it might kill a cold virus. Unlike mono, chronic EBV infection doesn't go away. It may be cyclical, with illness erupting perhaps one week in every four.

The general pattern is one of debilitating fatigue, chronic sore throat, joint and muscle pain and neurological symptoms such as headache and memory loss. Victims also may have fever, chills, swollen lymph glands, abdominal pain, vomiting, diarrhea, depression, anxiety, hair loss, rashes, weight loss, sensitivity to light, bladder problems, earaches, temporary paralysis after sleeping, and spleen and liver disorders.

It's not surprising, then, that chronic EBV infection is mistaken for other diseases, such as rheumatoid arthritis, multiple sclerosis, depression, mono, a connective-tissue disease called systemic lupus erythematosus, or just plain tiredness.

I've experienced most of those symptoms and heard many of those diagnoses applied to my affliction in the last 10 years.

In reasonably good health at the age of 29, I came down with pneumonia. After spending three weeks in bed, I got the welcome news that the spot on my lung was gone. At first, I thought the fatigue that followed was natural -- that I would regain my strength.

Instead, I remained tired no matter how long I slept. The calves of my legs swelled, and my joints began aching with alarming severity. The diagnosis was rheumatoid arthritis.

I didn't get well, but I did get better. Two years later, the pain and weariness had subsided to the point where I could work and attend college part time. Before, I couldn't walk a block without terrible exhaustion and aching in my knees. Now I could plod across campus -- if I took my time. I was still tired, but I didn't have to stop at every bench.

During the next three years, little changed. Then, in 1979, I got sick again during the flu epidemic. At first, the diagnosis seemed obvious: flu. The fatigue was almost indescribable. Two weeks in bed and I was no better. When classes began, I was spending 16 to 20 hours a day resting, dragging out only when I had to.

Chores that required even minimal effort now seemed impossible. I washed the kitchen floor at the rate of two square feet a day. I had to lie down after the briefest attempt to do anything. I relied on the telephone to stay in touch with friends I was too tired to visit.

Dissatisfied with my doctor's failure to investigate my poor health, I went to another, who referred me to the University of Arizona Health Sciences Center. Within 10 days, tests revealed I was infected with EBV. I'd never heard of it. I was told EBV causes mono -- which I had heard of -- and that I was suffering from a lengthy and severe case.

As the weeks passed, I grew uneasy. People who had mono recovered, but I felt worse and tests confirmed increased infection.

Two years came and went; I was still sick. By this time, it was well documented that other herpes viruses infected people on a chronic basis. Why not EBV? Then reports from medical researchers in other states began trickling back to my doctor. They, too, had patients like me, many ill for years.

I did not have rheumatoid arthritis, mono or a psychosomatic illness; I had chronic EBV infection. Finally, after seven years, I knew what was wrong.

Knowing helps a little, but it doesn't make me well. Doctors do not have an effective treatment for chronic EBV infection. Pain-killers and anti-inflammatory drugs provide some relief for those who can tolerate their side effects. Long hours of rest are a must, and during acute stages of the illness, hospitalization may be necessary -- especially when liver and spleen disorders flare.

The drug acyclovir, useful for some types of herpes infections, is now being tried against chronic EBV infection; newer herpes-killing drugs have not yet been tested on humans.

Until something that works comes along, people like me will just have to rest and wait and treat the symptoms. But at least now I know the enemy.

For more information: Chronic EBV Infection Support Group, c/o Pediatrics Department, University of Arizona Health Sciences Center, Tucson, Ariz. 85724. ualatin, Ore.