A man finds he is irritable for no particular reason and suddenly realizes that it has been two years to the day since his divorce became final.

A woman who lost her father to brain cancer gets a terrible headache on the anniversary of his death.

A woman feels mildly depressed every year over the holidays, wishing she could return to the happier days of the past—and develops respiratory illnesses every November and December.

Can the body somehow know that a person is holding on to grief? Could memories lower our immunity or trigger psychosomatic illnesses? Could our bodies remember an anniversary of a loss or trauma that our conscious mind has forgotten?

Many believe its possible to have old, unprocessed anger hidden in the unconscious—anger that affects a person’s energy field and body, even causing illness. Jungian analysts have suggested that unresolved emotional issues that have become buried in the recesses of the mind can cause people to become sick or develop physical pain and diseases. Sadness over a loss might arise as melancholy or emotional sensitivity on a particular day or at a certain time of year, or perhaps as a psychosomatic illness or flare up of symptoms of a condition. When you have an anniversary reaction of psychosomatic illness, the body might actually be creating a biochemical response to thoughts and emotions that the unconscious is holding on to.

An anniversary reaction, also known as the anniversary effect, can be linked to a day or perhaps a time of year or a season such as autumn or summer. Holidays often bring a complex mix of emotions as memories of joyful times, sadness, and disappointment intermingle. Maybe you feel you should be cheerful during the holidays but can’t sustain the emotion because the old feelings creep in. As a parent, you might feel obliged to be cheerful for your family’s sake yet be unable to let go of your old association between holidays and family conflicts. As a recovering alcoholic, you might find that guilt and shame about how you behaved in the past makes it hard for you to embrace the present and let go of your old emotions.

If you have ever had anniversary reactions, know that you can plan for them and use techniques for getting in touch with the old emotions so you can release them.

You can use the anniversary as an opportunity for healing.

Rather than repress any sensations, symbols, and wisdom that might arise from the unconscious and enter your conscious awareness, set aside time to allow this to happen. Rituals and ceremonies can help. Movement such as dancing can allow you to get in touch with anger, sorrow, or other emotions and let them out. You might make a ritual of running or hiking in a forest when an anniversary reaction is likely to happen. Let tears flow and the energy of anger propel you forward as you ascend a hill.

You might play a recording of a song from the past and dance to it, allowing your memories and the feelings connected to them to rise up and flow out of you. If as you dance or move, you encounter hidden feelings of guilt or shame, let them flow, too.

Even if you simply feel emotionally sensitive, short-tempered, or emotionally tired on the anniversary of a death or other loss, explore what you might be holding on to that you are ready to release. Releasing emotions makes it easier for your energy to shift and for new emotions to take the place of the ones you’ve let go of. Painting, cooking, writing in a journal, or playing a musical instrument might help you get in touch with the emotions you wish to release. You will experience them before they dissipate, but connecting to them and feeling them may help you in a healing process you did not realize was incomplete.

You might want to create a simple ritual and give it a beginning and end that can contain your experience so you do not become overwhelmed. Know that you can always release more of your anger, your grief, your survivor’s guilt, or your fear. Honoring your anniversary reaction in this way can help you to make space for new memories, emotions, and energies to take the place of the ones you were holding on to.

Insights may emerge as you do the work of releasing old emotions and opening up to new experiences that revitalize you. Notice afterward whether or not you feel better emotionally and physically, and what thoughts and insights arise in your mind. What might you change in the story of your life, having had this experience? What might you do differently, and what might you experience the next time the anniversary rolls around? Journal, reflect, and remember that you can change the story of what happened back then—and how your memory lives within you.