Reading a Day's Curve for the First Time

A single line on a graph can leave you unsure where to look first. There are four things to look for, and an order to look at them in.

In the graph

Response through the day
Time a dose was taken

An illustration generated for teaching. It does not represent the response to any particular medication or dose, and real curves differ from person to person.

A single curve holds four pieces of information: when the dose was taken, when it started to rise, how high it went, and when it came back down.

Being able to look at these four things separately is what makes the graph useful. A statement like “the medication worked well today” bundles all four together, so there’s no way to tell apart what was good and what fell short.

Each of the four points leads to a different story. If the rising point was pushed later, you look at the gap between the dose and meals along with it; if the peak was low, you look at that day’s conditions; if the coming-down point was early, you look at the relationship between how long it held and the interval between doses.

At first, just scanning through in this order is enough. After a few days of doing it, your eye starts going to those spots on its own.

People often put it like this

I look at the graph, but I don't know what to look at
The line is jagged — did I record something wrong?
Looking at just one day, I can't really tell
It looks good, but I can't explain what's good about it

Why this can happen

Below are factors often discussed alongside this pattern. This is not a list of confirmed causes, and more than one is often in play at once.

First, find the dose marker It's the small triangle below the horizontal axis. The other three points are all measured as a distance from this one, so this is where to start.
Second, the point where the curve starts to rise This is where the line lifts off the bottom. The horizontal distance from the dose marker to this point is the first value to look at.
Third, the highest point How high it climbed, vertically. Rather than reading the number on the axis, compare it against other days and other doses.
Fourth, the point where it starts to come down Look at how far ahead of the next dose marker it is. This is where the length of time it held up comes from.
And line up several days side by side Something that looks like just that day's circumstances when you look at only one day reveals itself, once a few days are gathered, as either a repeating pattern or not.

Try recording this for a few days

The time of the dose This is the first reference point. If it's uncertain, the other three points all become uncertain too.
The time you felt things start to change This becomes the second point.
The best time, and your output then This becomes the position and height of the third point.
The time things started to feel heavy again This is the fourth point. Without it, the entire right side of the peak is left empty.

What you could show your care team

A record is material for describing your situation. Decisions about which medication you take, at what dose, and at what time belong with the clinicians who look after you.

Frequently asked questions

The curve looks jagged — did I record something wrong?

No. If the times you recorded are spread far apart, the curve is drawn that way too. As you record more often, it naturally smooths out.
Is it okay if the vertical axis has no numbers?

Yes. It's enough to read whether it's higher or lower compared with other days and other doses. This isn't a lab value — it's a comparison within yourself.
Looking at just one day, I can't really tell.

That's normal. A single day's curve carries a lot of that day's particular circumstances, so you usually need to line up three days to a week's worth before repeating patterns start to show.
What does it mean when there's an empty stretch in the curve?

It usually means there was no record for that time. It's not that nothing was happening in the body — it's that nothing was written down.