Joan, 68, got an injection to treat knee pain due to osteoarthritis. She had gotten such injections in the past, and the experience hadn't made much of an impression on her. This time was different. Nine days later, she landed in the emergency room because her knee now hurt so much that the pain was unbearable. They sent her home, saying that it was just a reaction to the shot.

The next day, she went to see her doctor, saying, "I can't take this pain anymore." It was Friday, and he told her to wait and see if the knee calmed down over the weekend.

By Tuesday, she was delirious, and an ambulance took her back to the emergency room. This time, she was diagnosed with a staph infection in her knee. She also had developed sepsis, which the Mayo Clinic terms "a potentially life-threatening complication of an infection."

The Mayo Clinic goes on to say, "Sepsis occurs when chemicals released into the bloodstream to fight the infection trigger inflammation throughout the body. This inflammation can trigger a cascade of changes that can damage multiple organ systems, causing them to fail."

To deal with the infection, Joan had emergency surgery on her knee and was started on antibiotics delivered through an IV (intravenous) line. She would need to continue the IV antibiotics for six weeks.

Notice that it took three tries before care providers correctly identified the cause of her pain - it wasn't until she showed up in the emergency room the second time, delirious and experiencing hallucinations, that they stopped telling her that she simply needed to wait for the pain from the injection she had gotten two weeks earlier to subside.

What steps can you take to help avoid similar delays in your care?

First, before you have a treatment, ask what to expect afterwards and roughly how long it should take to get back to normal. In some cases, "normal" will never return. Then it's important to know what the "new normal" is expected to be like, and how long it is likely to take to reach it.

As an example, if you ask about a planned injection, in some cases your doctor might tell you that you could have some immediate soreness that will go away within a few days. In other cases, if the area is numbed before the injection, you may feel fine right away. Later that day, however, when the anesthetic wears off, pain may be severe. Your doctor might explain that significant pain is to be expected, but that it will subside over the next several days.

Second, once you know what to expect, you or your advocate can raise a red flag about a symptom that arises after treatment if its intensity, progression or persistence seem unusual to you. Include comparisons and timeframes.

For example, you might say, "I got an injection of Drug X nine days ago. I have had the same drug injected in the past and after three or four days, the pain from the injection was always gone. This time, the pain started out about the same, a 3 on a 10-point scale. But this time, instead of decreasing, the pain has increased until now it's a 10, nine days later. This isn't my body's normal reaction to this shot. What else could be going on?"

While of course responses to treatments vary from person to person and even in the same person over time, if the symptom is not normal for you and is disrupting your life, be persistent in seeking appropriate care. Doing so can be a challenge for anyone. How do you draw the line between accepting the conclusions of medical professionals and relying on your knowledge of your own body?

It can be very helpful to have someone who knows you well act as an advocate on your behalf. This is someone who can say to the doctor, "Look, something is really wrong. She never lets pain stop her from getting on with her life. But for the last two days, she has hardly moved. She can't even watch television - she's in too much pain. What else could be going on here?"