Prep first
Before you start
- Blot, don't rub, with a clean white cloth.
- Keep heat away: no dryer and no iron.
- Start with cold water and soak for about 30 minutes.
- Test a hidden seam before any remover touches the spot.
An unknown stain on your sheets is any mark you can't put a name to yet. Some turn out to be sugary drinks that dried out of sight, detergent or softener residue, or bleach carried over from the washer, and many only show up after a wash. Since you can't tell what it is yet, go gently: cold water, then detergent or an enzyme presoak, and keep heat well away from it.
Random blood stains on sheets do best with a patient soak, so give the spot time to loosen before you rinse. If a mysterious yellow stain on sheets doesn't lift after one round, repeat the gentle steps before reaching for anything stronger. Save oxygen bleach for the stubborn spots, and check the care label before using it on silk or satin.
Before you start
What sheets, towels & table linens can take
Safe to use3
- Water
- Soaking
- Enzyme cleaners
Use with care6
- Hot water
- Chlorine bleach
- Oxygen bleach
- Solvents (alcohol, spot removers)
- Acids (vinegar, lemon)
- Scrubbing and abrasives
Avoid1
- Heat, once the stain is out
6 items
What you'll need
Tap an item to get it on Amazon, or tick what you already have.
- Clean white cloth or paper towelBlots up the stain without transferring dye. (opens Amazon)
- Dull knifeLifts dried crust without tearing the fabric.
- Cold water and a basin or sinkStarts the soak without setting the stain. (opens Amazon)
- Liquid laundry detergent, shampoo or dishwashing liquidLoosens the spot when worked in gently. (opens Amazon)
- Enzyme laundry presoakBreaks down protein stains like blood while you sleep. (opens Amazon)
- All-fabric (oxygen) bleachThe gentler bleach for colorfast sheets. (opens Amazon)
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7 steps
Step by step
Step 1 of 7
Blot and check the label
Blot the spot with a clean white cloth or paper towel, pressing rather than rubbing. Scrape off any dried crust gently with a dull knife. Check the care label, and if the sheet is dry-clean only, take it to a dry cleaner promptly instead of treating it at home.
Tip. Dab from the outside of the spot toward the middle so it doesn't spread.
Step 2 of 7
Test on a hidden seam
Put a little of the cold water and detergent you plan to use on a hidden seam or hem. Check it before you go on to the stain.
Careful. Stop if the color changes or the fabric looks damaged.
Step 3 of 730 minutes
Soak in cold water
Lay the sheet in cold water so the spot is fully covered, and leave it for about 30 minutes. Cold water is the right first move on a stain you can't identify, because heat can set it.
Step 4 of 730 minutes
Work in detergent, then rinse
Work a little liquid laundry detergent, shampoo or dishwashing liquid into the spot with your fingertips, pressing gently. Leave it for about 30 minutes, then rinse the spot in cold water.
Step 5 of 7
Overnight enzyme presoak
Cover the spot with an enzyme laundry presoak, or with detergent if you have none, and leave the sheet to soak overnight. In the morning, wash it in warm water, not hot, and check the spot before anything else.
Tip. If the spot has faded but not gone, wash again before you go on.
Step 6 of 7
Pretreat what's left with oxygen bleach
If a mark remains after the wash, pretreat it with an all-fabric (oxygen) bleach that passed a colorfastness test on a hidden seam. Rinse it out fully, then air-dry the sheet and check the spot in daylight.
Careful. Leave liquid or gel pretreatments on for no longer than the label says, since bright dyes can change color or fade.
Step 7 of 7
Last resort: diluted chlorine bleach
Use this only on white cotton or linen that is colorfast to chlorine, and only if the label allows it. Dilute the bleach with water following the package directions, and soak the spot briefly. Rinse it out completely before washing as usual, and only after everything else has been rinsed out.
Careful. Never use chlorine bleach on wool, silk, spandex or colored sheets.
If you'd rather buy than mix
Best products for unknown on sheets, towels & table linens
Choose a prewash stain remover spray or stick and an oxygen bleach powder, and check the label for colorfast use before you buy.
Clorox 2 Laundry Stain Remover and Color Booster Powder, 49.2 Ounces
How we picked these: each product is made for this type of stain, its maker doesn't warn against using it on sheets, towels & table linens, and its directions fit the steps above.
Finished the steps? How does it look?
Nice work. Let it dry completely and check it again in good light before using any heat. Here is what done looks like:
How to tell it's really gone →A faint mark usually needs one more round, not a stronger product.
Heavy buildup usually takes more than one round.
Heavy or long-standing buildup →When to call a professional →How to tell it's working
With a mystery mark, the first sign of progress is color lifting onto your white cloth as you blot, and the edges of the spot turning paler after the soak. If the sheet looks unchanged after the enzyme soak and nothing transfers when you blot, the mark has probably set into the weave and needs the dried-stain approach.
What changes for yours
Adjust for your sheets, towels & table linens
White cotton sheets
White cotton can take the full method, including chlorine bleach as the last step if the label allows it. Work the cold soak and detergent first, and only move to bleach after the warm wash.
On white cotton the overnight enzyme presoak does most of the work. Check the spot in daylight before drying, and keep the sheet out of the dryer until it's gone.
Colored cotton sheets
Colored sheets skip chlorine bleach entirely, and the oxygen bleach comes in only after a colorfastness test on a hidden seam. Keep the cold soak and detergent steps exactly as they are.
If a color changes during the test, stop and rely on the enzyme presoak alone. Dyes can fade if any pretreatment stays on longer than the label says.
Polyester and microfiber sheets
Synthetic sheets take the same cold-water start, but use hand-hot water in the wash rather than the hottest setting. We'd stop at the oxygen bleach here rather than reach for chlorine.
Give the detergent work-in its full 30 minutes before rinsing. If the spot is still there after the overnight presoak, pretreat with the oxygen bleach and then stop.
Silk and satin sheets
Silk and satin need the gentlest version of this method, with cold water and a little detergent and no bleach of any kind. Work the detergent in with a clean white cloth rather than your fingers, and rinse in cold water.
Leave out the overnight presoak and every bleach, since these fabrics are easily damaged. If the spot doesn't lift after one soak, take the sheet to a dry cleaner rather than trying a stronger product.
Heavy or long-standing buildup
If the stain is old, it has probably been through several washes, and that makes it harder to remove. Fresh stains are much easier than old ones, but this method still works on older ones if you give it time.
For dried blood, scrape off the crusted part first, then soak in cold water with detergent or an enzyme presoak. Repeat the overnight presoak if the spot still shows, because one soak rarely finishes an old stain.
Chlorine bleach is the final option, and only on fabric that can take it. If the mark is still there after that, it's usually safer to stop and take the sheet to a dry cleaner than to keep pushing it.
Vinegar, baking soda, peroxide and more
Do home remedies work on unknown on sheets, towels & table linens?
Plenty of home remedies float around for blood and mystery marks. Most of them don't suit this stain, and some can set it or damage the sheet. Here is where each one lands.
Works2Skip4
Chemical safety
Never mix these
Some products in this guide react dangerously with each other. Use them one at a time and rinse with water in between.
Chlorine bleach + Oxygen bleach (OxiClean)
Both makers advise against combining them: OxiClean says not to mix it with chlorine bleach, and Clorox says the two bleaches cancel each other out.
If they mix by accident: Don't use the mixture; ventilate the room and avoid breathing fumes or touching it; call Poison Control at 1-800-222-1222 for disposal advice or if anyone feels unwell.
What makes it worse
Mistakes to avoid
Don't blot with colored cloths
Colored cloths and sponges can bleed dye onto the sheet and leave a second mark. Use a clean white cloth or paper towel every time you blot.
Don't rub it with bar soap
Bar soap sets many stains, so it has no place on a fresh spot. Work in liquid detergent instead.
Don't skip the hidden seam test
Even a gentle detergent can fade or change the color of a dyed sheet. Check a hidden seam or hem first, every time.
Don't reach for chlorine bleach on silk or satin
Chlorine bleach is off the table for silk and spandex, so keep it away from satin or silk sheets even as a last resort. An enzyme presoak is the gentler step for these, and anything stronger needs a test on a hidden seam first.
Don't use chlorine bleach on a rusty-looking mark
If the mark is orange or brown and looks like rust, chlorine bleach makes it darker and harder to lift. Reach for a rust remover first and test it on a hidden seam, since some are harsh on colored cotton.
Don't try milk or other kitchen fixes on a mystery mark
Milk adds a protein stain on top of the one you already have, which leaves you with a bigger problem. Stick to cold water and detergent until you know what you're dealing with.
When to call a professional
Sheets labeled dry-clean only should go to a cleaner as soon as you notice the mark, since home treatment is off the table for them. For washable sheets, a cleaner is the smarter call when the mark has spread over a wide patch or the weave is delicate, and say you couldn't identify the mark and which fiber the sheets are made of.
Questions
Can blood come out of sheets after it has dried?
Often yes, but it takes more patience. Soak the dried spot in cold water, then leave an enzyme presoak on overnight. Keep it away from the dryer until the stain has gone.
What if I can't tell whether the stain is blood?
Start with the same gentle steps anyway. Cold water and detergent are the safest first moves on a stain you can't identify, so you lose nothing by starting there.
Does vinegar help a blood stain on sheets?
No. Vinegar is an acid that can weaken cotton and change its color, so skip it on a blood stain. Its acidity can weaken cotton and shift the color of a sheet, so it's a poor choice.
Can I use a store-bought stain remover on sheets?
Yes, after the cold soak, if the label says it's safe for the fabric. Test it on a hidden seam first and rinse it out fully before the wash.
What should I do if the sheet is dry-clean only?
Take it to a dry cleaner promptly rather than treating it at home. Tell them it's a blood stain and what fiber the sheet is made of.
What if the stain is still there after the wash?
Repeat the overnight enzyme presoak, then try the oxygen bleach on what's left. Keep the sheet out of the dryer until the spot is gone.
Can I wash white sheets in hot water once the mark seems gone?
Hold off until the mark is truly out, since hot water can lock a protein stain in before you've identified it. Once cold soaking and detergent have done their work and nothing shows on a white cloth, a very hot wash is fine for cotton.
Are chlorine bleach and colored sheets a safe mix?
Chlorine is the final fallback, and only when the care label permits it and a bleachability check passes. A sheet that bleeds dye during that check is a sign to switch to oxygen-based products instead.
Is it okay to leave a plain detergent mix on the mark overnight?
Yes, if you don't have an enzyme presoak, a little liquid detergent worked into the mark can sit overnight in its place. Rinse it out in the morning and check the spot before you move on to anything stronger.
Unknown on other materials
Other stains on sheets, towels & table linens
Start from the bigger picture
How we know this
Every method, amount and warning here comes from university extension services, industry bodies and product makers. We read them, check every step for unsafe combinations and changed amounts, and write it up so you can follow it.