Track Herpes (HSV-1 and HSV-2) and Catch the Prodrome Early

What to track during an outbreak, and in the days before one

The recognisable sore is only part of the picture. The entries that change what you do are the early ones, before anything is visible, and the pattern across months rather than any single episode.

• Tingle / Prodrome is the itching, tingling, burning or mild pain that often arrives hours to a day or two before a visible sore, usually at the same site each time. This is the single most useful thing to log in herpes, because episodic antiviral treatment works best started during this window, and most people, asked cold, cannot say how long their own prodrome usually runs or what it feels like, until a week of dated entries answers both.
• Cold Sore is the oral lesion, usually at the vermilion border of the lip, sometimes just inside it. Log the day it appears and roughly how many days it takes to crust and heal, because your own healing timeline, once logged a few times, is what lets you recognise the next one early rather than after it has already opened.
• Genital Sore is the same lesion at the genital site. Either HSV-1 or HSV-2 can cause it, and the virus behaves the same way there regardless of which type it is. Logging the count and clustering of episodes over several months is exactly the data a clinician uses to judge whether your recurrence rate is high enough that suppressive therapy is worth discussing.
• Nerve Pain is a deeper, sometimes shooting pain along the nerve root, distinct from the surface tingle of the prodrome and occasionally present without any visible sore at all. Some people get this every time, some almost never, and logging it separately shows you which kind of recurrence you tend to have.
• Swollen Glands, tender lymph nodes near the site, are more common with a first episode or a larger recurrence than with a mild one. A pattern of glands swelling every time you have an outbreak is useful for telling a real recurrence apart from unrelated skin irritation.
• Burning Urination can accompany a genital outbreak, particularly when a lesion sits near the urethral opening. Logging it separately from the sore itself matters if a clinician later needs to work out whether an episode is herpes, a urinary tract infection, or both at once.
• Dry / Itchy Skin is the mildest end of a recurrence, and for some people it is the only version they ever get, with no visible sore at all. It is easy to dismiss and easy to under-log, which is exactly why logging it matters: it may be your actual, usual pattern rather than a false alarm.
• Fever, typically 38°C (100.4°F) or above, is more common with a first episode than with later recurrences and points to a systemic viral load rather than a purely local one. Log it alongside the site of the outbreak so a first-episode pattern is not mistaken for an unrelated illness.
• Headache can accompany a first episode or an unusually large recurrence. Logging its timing against outbreak onset is what separates a herpes-related headache from an ordinary one that happened to land the same week.
• Fatigue is common with first episodes and, for some people, with the day or two around a recurrence. Logged daily, it can act as an early flag alongside the prodrome, or simply confirm that a rough week was, in fact, connected to an outbreak you might otherwise have logged as unrelated tiredness.
• Reduced Daily Function is what a recurrence actually costs you: a missed shift, a cancelled date, discomfort sitting or walking, avoided intimacy. It is the line a clinician reads first when deciding whether your frequency and severity justify suppressive therapy rather than treating each episode as it comes.

The factors people report before a recurrence, and the medication log that ties it together

Triggers for herpes are real but individual. Stress and poor sleep are the two most consistently reported across both oral and genital disease, but the point of logging is to find your own pattern, not to adopt someone else's list.

• Antiviral Medications is where episodic and suppressive treatment both live in your log. An episodic dose taken during the prodrome, logged against how many hours after the tingle you actually took it, tells you and your prescriber whether you are catching outbreaks early enough for the drug to do its job. A daily suppressive dose, logged for months against recurrence dates, is what turns "it feels less frequent now" into an actual number.
• Stress is the most commonly reported trigger for recurrent herpes, oral and genital alike. Logging it is not about proving stress causes outbreaks, it is about checking, for your specific pattern, whether a stressful stretch reliably precedes one.
• Poor Sleep is grouped with stress as a common precipitant. A run of short nights before a recurrence is worth logging on its own, separately from how stressed the week felt, because the two do not always move together.
• Sun / UV Exposure on the lips is a well-established trigger for oral recurrences specifically, not genital ones. If your cold sores cluster after a day skiing, at the beach, or just in strong spring sun, this is usually why, and it is worth testing whether an SPF lip balm changes your pattern once you have a baseline logged.
• Great Sleep is worth logging too, not just the bad nights, so a run of good ones gives you a baseline against which a bad stretch actually stands out.
• Physical Activity at ordinary levels is not something to worry about. Log it mainly so an unusually intense or exhausting stretch, the kind that also disrupts sleep, can be checked against your recurrence pattern like any other factor.
• Alcohol is reported by some people as a trigger, though the evidence for a direct link is mixed and this seems to be genuinely individual. Logging it settles the question for your own body instead of leaving it as a guess either way.
• Sexual Activity can involve local friction at either site, which some people find precedes a genital recurrence. Logging activity alongside lesion onset is the only way to see whether that pattern actually holds for you, without turning every encounter into something to worry about afterward.

Why the prodrome is the moment that changes what a tablet can do

Episodic antiviral treatment, aciclovir, valaciclovir or famciclovir, works by slowing viral replication, and replication is fastest in the first day of a recurrence. Started during the prodrome or within about twenty-four hours of the first visible sign, it can shorten an episode meaningfully. Started on day three, once a cold sore or genital sore is already open, the same tablet does much less. This is the entire reason the prodrome matters more than the sore itself.

The difficulty is that most people cannot describe their own prodrome accurately from memory. Ask someone with recurrent herpes how long their tingle usually lasts before a sore appears, or whether it is always at the same spot, or whether it is ever a false alarm that resolves without a lesion, and most cannot answer with any confidence. A week of dated entries answers all three. Log the tingle the moment you notice it, log whether a sore followed and when, and after two or three cycles you have your own number: how many hours you typically get, and how reliable the warning actually is.

That number is what changes behaviour. If your prodrome reliably runs twelve hours before a sore, you know you have a genuine window to take antiviral medication rather than a hope. If it turns out your tingle is unreliable, sometimes a false alarm, sometimes no warning at all, that is useful information too, and it may be part of the conversation about whether suppressive therapy, taken daily rather than triggered by a warning sign, suits you better than treating each episode as it comes.

Suppressive therapy, transmission, and preparing for a clinic visit

Suppressive therapy, a low daily dose of the same antiviral drug class used episodically, works differently. Its benefit is a lower recurrence rate over months, not a shorter individual episode, and a lower rate is exactly the kind of change that is invisible without a dated record. Someone who had three recurrences in the three months before starting, and one in the three months after, has a result. Someone going on general impression alone, "it feels better," has an opinion, and a busy prescriber has to take that impression on trust rather than evidence. Logging genital sore or cold sore episodes for a few months before a suppressive therapy conversation, then continuing through it, is what turns the decision into something you can actually evaluate together, including whether it is worth continuing past the review point most clinicians set.

Transmission is worth addressing plainly, briefly, and then leaving alone. Herpes can be passed on even when no sore is visible, through asymptomatic viral shedding, and suppressive therapy measurably reduces that risk in addition to reducing recurrences. Condoms reduce risk further without eliminating it, since they do not cover every area where shedding can occur. None of this is a reason for alarm or for avoiding intimacy, and it is not something to work out alone from a website. A sexual health clinic is the right place for that conversation, including questions about disclosure, timing, and specific risk in your situation, and they will have had it many times before.

A doctor-ready PDF from Trace Health turns weeks or months of entries into a chart a clinician can read in under a minute: recurrence frequency and severity, the antiviral medication timeline, and how close to the prodrome each dose was taken. Whether you are seeing a general practitioner, a dermatologist or a sexual health clinic, that is a faster and more accurate starting point than reconstructing the last few months from memory in the first two minutes of an appointment.

Frequently asked questions

Can Trace Health tell me whether I have herpes?

No, and it is not built to. A diagnosis needs a clinician, usually a swab test taken directly from an active cold sore or genital sore while it is present, since that is the most reliable way to confirm the virus and which type it is. A type-specific blood test can help in some situations, such as when there is no visible lesion to swab, but it has real limitations that a clinician needs to explain, including the chance of a result that does not change what you should actually do next. What Trace Health can do, once you have a diagnosis, is give you a record more reliable than memory: how often episodes happen, how severe they are, how long your prodrome runs, and what tends to sit in the days before a recurrence. That record does not diagnose anything. It is evidence you bring to a clinician who already knows what you are dealing with, to help decide on treatment, not evidence you use instead of seeing one.

How does logging actually help me catch my prodrome earlier?

Most people cannot describe their own prodrome from memory: how many hours of warning they typically get, whether it is always the same spot, or whether a tingle sometimes resolves without becoming a sore at all. A week or two of logging answers all three. Note the moment you notice tingling, itching or burning, then note whether and when a cold sore or genital sore follows. After two or three cycles you have your own number rather than a guess, and that number tells you whether you have a genuine window to take antiviral medication episodically, since that treatment works best started during the prodrome or within about a day of the first visible sign, and does much less once a sore has already opened. If your logs show the prodrome is unreliable for you, sometimes a false alarm, sometimes no warning at all, that is useful too, and it is worth raising directly with a clinician, because it may point toward suppressive therapy suiting you better than an as-needed approach that depends on a warning you cannot always trust.

Will this help me and my clinician decide about suppressive therapy?

Yes, more directly than almost anything else you could bring to that conversation. Suppressive therapy's benefit is a lower recurrence rate over months, and a lower rate is invisible without dated entries to compare against. Logging genital sore and cold sore episodes, including severity and how much they cost you in daily function, for a few months before you raise the topic gives a clinician an actual baseline rather than your general impression of how bad things have been lately. If you start suppressive therapy, continuing the same log afterward is what lets you both see whether the frequency genuinely dropped, by how much, and whether it is worth continuing past the review point most prescribers set, commonly around a year. It is also useful for the opposite finding: if your logged recurrence rate turns out lower than it felt from memory, that matters too, and the decision stays yours and your clinician's, made from an actual record instead of a sense that things have been rough.

Can I pass on herpes to a partner even when I have no symptoms?

Yes, this is real and it has a name, asymptomatic viral shedding, and it is worth knowing plainly rather than worrying about vaguely. The virus can be present on the skin and transmissible on days with no tingle, no sore and nothing visible at all, which is part of why herpes is so widespread and why it is never fair to assume you know how or when it was passed on, in either direction. Suppressive therapy measurably reduces the risk of transmission, in addition to reducing how often you get recurrences yourself, and condoms lower risk further without removing it entirely, since they do not cover every area where shedding can occur. Logging your prodrome and outbreak dates in Trace Health can help you see your own pattern, but it cannot tell you when you are shedding without symptoms, since by definition there is nothing to log on those days. Questions about disclosure, timing and specific risk in your situation are exactly what a sexual health clinic is for, and they will have answered them many times before. This page will not turn that conversation into something you have to work out alone.

Is my log private, given how much stigma still surrounds herpes?

Your entries stay on your iPhone by default, with optional private iCloud sync to your own Apple account. There is no Trace Health account to create, no sign-up, and nothing is uploaded to a server for analysis. That matters here specifically, because a herpes log can end up touching sexual health, sexual activity and medication together, and plenty of people logging this are doing it precisely because they do not want that information sitting anywhere else. Nothing leaves your phone automatically, and nothing is shared with a partner, a clinician or anyone else without you actively generating a PDF and choosing to send it. Herpes is extremely common and rarely serious, but the stigma around it is disproportionate to the medical reality, and you should not have to weigh that stigma against whether it feels safe to keep a record of your own health.