You have a deadline, a sick parent or a lease that is ending, and you feel wound up. Is that stress, anxiety, or plain worry? People use the three words as if they meant the same thing. Official sources define them differently, and the differences are useful.
This article sets out those definitions and what clinicians look at when they decide whether anxiety has become a disorder. It is not a self-test. Nothing here can tell you whether you have an anxiety disorder. Only a clinician who has talked with you can assess that.
What is the difference between stress and anxiety?
Stress has a cause you can point to. The National Institute of Mental Health (NIMH) defines stress as "the physical or mental response to an external cause, such as having a lot of homework or having an illness." It describes anxiety as "your body's reaction to stress," one that "can occur even if there is no current threat." Its fact sheet sums up the contrast in two lines:
- Stress: "Goes away once the situation is resolved."
- Anxiety: "Is constant, even if there is no immediate threat."
The definitions are not identical everywhere. The American Psychological Association's dictionary defines stress as "the physiological or psychological response to internal or external stressors," which allows for causes that come from inside you as well as from outside. NIMH speaks only of an external cause. On both definitions, stress is a response to something.
Where does worry fit?
Worry looks ahead. The APA Dictionary of Psychology defines it as "a state of mental distress or agitation due to concern about an impending or anticipated event, threat, or danger." Worry is about something that has not happened yet.
The dictionary then draws the distinction that matters: "Difficult to control, persistent and excessive worry is a main symptom of generalized anxiety disorder." Worry by itself is not the symptom. Worry that is hard to control, persistent and excessive is.
When is worry doing its job?
Much of the time. The Merck Manual puts it this way: "Anxiety is a normal response to a threat or to psychological stress." The American Psychiatric Association describes normal stress as something that goes away after the stress passes and feels manageable.
In practice, ordinary worry tends to be tied to a real situation, to point toward a step you can take, and to settle once you have taken it or the situation has passed. You worry about an exam, you study, the exam ends, and the worry goes with it. That picture is an illustration of the definitions above. It is not a clinical test.
What do clinicians look at?
They look at how the anxiety behaves more than at what it is about. The American Psychiatric Association says that for a diagnosis of an anxiety disorder, symptoms must be out of proportion to the situation, persistent, and interfere with daily functioning. The Merck Manual describes what doctors weigh in similar terms. Put together:
- Distress. The anxiety is very distressing. The American Psychiatric Association's wording for a possible disorder is that it feels overwhelming and hard to control.
- Interference. It interferes with functioning, for example with work, school or relationships.
- Duration. It is long-lasting or keeps coming back, where ordinary stress passes with the situation.
- Proportion. It is out of proportion to the situation.
Each diagnosis has its own time frame. For generalized anxiety disorder, NIMH says a person must find it difficult to control worry on most days for at least 6 months, along with other symptoms. A clinician weighs all of this in conversation with you.
The Merck Manual is frank that the line is not sharp: "People's ability to tolerate anxiety varies, and determining what constitutes abnormal anxiety can be difficult." The separate diagnoses are described in types of anxiety disorders.
Can stress turn into an anxiety problem?
NIMH treats it as a possible risk, not a certainty. Its fact sheet says you may be at risk for an anxiety disorder if it feels like you can't manage the stress and if the symptoms of your stress interfere with your everyday life, cause you to avoid doing things, or seem to be always present. NIMH also notes that the symptoms of generalized anxiety are often worse during times of stress.
So a hard season does not mean you have a disorder. It is also not a reason to dismiss what you feel. If the stress seems to be always present, or you have started to avoid things, those are among the signs NIMH lists.
Many stressful situations are changes: a move, a new job, a graduation, a breakup. The practice has a page on therapy during life transitions for readers in that position.
What can you do with this?
Use it to describe what is happening, not to label yourself. A clinician may ask whether there is a situation driving the feeling, whether it eases when the situation does, how much of your day it takes and whether it is stopping you from doing things. Noticing those in advance makes the conversation easier.
NIMH's general advice on mental health is to seek professional help if you are experiencing severe or distressing symptoms that have lasted 2 weeks or more. On anxiety specifically, it says that when anxiety starts to cause problems in everyday life, such as at school, at work, or with friends and family, "it's time to seek professional help." The American Psychiatric Association adds that the first step is often to see your doctor, to rule out medical conditions that may cause similar symptoms.
NIMH also says that practicing a healthy lifestyle, with choices such as reducing caffeine intake and getting enough sleep, can help combat anxiety, although this alone cannot replace treatment.
Dr. Rabin offers anxiety therapy in Brookline and by telehealth across Massachusetts. Her approach looks at what drives the anxiety, such as recurring themes and relationship patterns, as well as how to respond to anxious thoughts and physical sensations in the moment. Not everyone who worries needs therapy. Do I need therapy for anxiety? goes through that question, and the practice's article on signs you may need therapy covers the wider picture. You can request a free consultation of about 15 minutes through the contact page.
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Last reviewed October 2026. This guide is general information, not medical advice or a diagnosis. If you are in crisis, call or text 988, or call 911 in an emergency.
